Sorry its a long one to read by I need help...
This might sound crazy and maybe I'm just lame but...
I know normally they go by the 1st day of your last cycle. Well in my situation it's not possible bc back in the beginning of Aug I had my 4th miscarriage and so sometime in Sept is when we are thinking I got pregnant. And ive been told by a different doctor lon ago that a miscarriage could kinda be like a chcle bc its a cleaning out of the uterus like a period cycle does. I didnt have a period i just had a miscarriage. So there is not a date for my last cycle.
So with that said my doctor said my due date would be June 16th. A couple months ago a gf of mine asked me if the dr gave me a 9 month or 10 month calculations for my due date b her brothers wife got a 10month due date. But from Sept to June is (sept, oct, nov, dec, jan, feb, mar, apr, may, June)... That's 10months right or is that 9 months?
Ok now for months I've been explaining the weekly update to the hubby about the fetal development and what to expect and we thinking it was every Saturday which would mean I was 30 weeks this past saturday. But I went to the doctor on Tuesday and he said I was going to be 31 weeks on Thursday (today)...
It's so confusing...
The ultrasound printout we got said 30 weeks and 5 days which would make us 31 on Thursday as the doctor said but...
Looking at online things like tickers and update things for Facebook is telling me that June 16 would keep us 30 weeks til Saturday... I absolutely love my doctor and he seems to know what he's doing but I'm confused...am I the only one?
Someone please help me understand this all...

They normally only go by your LMP date until your 12 week scan and then they go by how big baby is I think. I would go by whatever due date your got at your scan rather than facebook/tickers etc (tickers will be different depending on how many days your cycle is etc.)

I had a miscarriage the cycle before I got pregnant.

The bleeding/miscarriage started on August 4th so my doctor used that as the first day of my last period when calculating my due date. All my scans have matched up with that date (she gave me one at 6 weeks to make sure I wasn't still pregnant from the miscarriage, had one at 10 weeks and 19 weeks as well.) So I would go by the date you first started bleeding on your last cycle (even if it was a miscarriage.)

When was ur FIRST ultrasound and what did the doctor us than? Ultrasounds used after 20 weeks are not the best indicators for a dating scan and tend to be off, however, ultrasounds before 12 weeks are better...

Now, my question is, before you had your fourth miscraige(and sorry to hear that ), can you figure out how your cycle would have been if you were not pregnant? If you had a regular cycle this should be easy it would give you an estimated idea of when you would have expected ur period in aug/sept.

I'm confused by the whole due date thing too.
My LMP lasted like a whole day and a half, if I count the spotting off (when it normally lasts at least 3 days-full on, then just ends-sorry TMI). When I first went to the doc, I explained my "period" and was never given a specific due date, eventho on all the calculators based on my LMP, I'm due July 15/16. They gave me an ultrasound that first visit too, when I was told he was measuring 4 days ahead. That doc left the practice or something, bc I haven't seen him since, and now I'm back to my "original" OB/GYN, who seems to know her stuff a LOT more-not saying that the last didn't.
The first appointment I had with her, she asked if I was given a due date yet, and I explained my LMP again to her and told her that I was never given a specific due date. She says he's going to be a big baby, but still has yet to give me some kind of due date. I'm assuming they're now going based on MY adjusted due date-my ticker.
Even after all of this, my mom and SIL think I'm at least a month ahead of what I think and will have him sometime in June.

My due date would be way way off if taken from lmp, as i ovulated on cd48. What did your first scan date give?

Your edd is based on 40 weeks (as I'm sure you know). Yes conceiving in September and being due in June is over a period of 10 months but you can't count the whole of September because you would have conceived towards the end. My dates work out it happened on the 5th or 6th of Sept and I'm due 27th May which is 9 months. If you go by your due 16th June I agree you should start your new week on a Saturday. It sounds like maybe when you had a scan they may have changed your due date without you realising due to the size of your baby. Going by those dates your edd would be 14th June which is only 2 days earlier. Don't forget they are only estimated due dates and try not to get too hung up on actual dates they are both close dates so just expect baby hopefully sometime that week. Hope that helped x

My SIL is in a similar situation-- she miscarried on Oct 1, then became pregnant again without a menstrual period in between. They gave her a due date of July 23, but they are counting her weeks in fetal age instead of gestational, so on July 23 she'll be 40 weeks fetal, and 42 weeks gestational. This makes no sense to me bc a due date (in the USA especially) is supposed to be 40 weeks gestational. I keep trying to tell her that her 'real' due date (in the way that most people talk about it) is actually July 9th, and that she becomes full term (37 weeks) mid-June. It seems awfully irresponsible for her doctor to have given her such confusing info, but supposedly he gave her a 'drop dead' due date-- anything after it would mean an immediate induction... why can't they just make these things uniform?!

Thank you so much everyone...my first scan was at 8 weeks and that was back in november...and midget em yes I agree about he due date being the 14th but it's a baby and can be unpredictable I know =) but I do appreciate everyone's helpful thoughts and experiences =)