Negative tests and 3 weeks late? Help!!

[Beautiful323]

AF came in March as usual the 6th through the 13th.. very heavy, clotty, no cramps, everything was normal. Two weeks later I started what I thought was AF again, 10 days early. It lasted for 5 days and was VERY light-only needed liners, very tiny clots the last two days, and mild cramping.
I took two hpt the first week of April, both were negative. I had a urine test at the doctors April 18th, also negative, I had a blood test done April 21st, also negative. I just took another hpt at about 7:30 pm, also negative.
If I got by my original start date for this month, the 6th, I'm over 3 weeks late, going by the new start date (counting the 5 day bleeding as AF) I'm about a week late.
What could be causing this if I'm not pregnant?
Could I still be pregnant even with all the tests coming back negative?
I still have one test left, should I take it in the morning or wait a week and test again if AF hasn't shown up yet?

 

[laura109]

If you normally have regular cycles u deffo need to go to the doctors about it because its strange ur ad has not arrive. I doubt all them tests could be wrong x

 

[Beautiful323]

I think I've got everything figured out now My doctor thinks I have PCOS, I had blood work done yesterday and I go for a pelvic ultrasound next Friday.