TTC 2 years & Confused

[RNA2012]

Me and DH have been TTC for 2 years now. Back in January we switched things up and instead of trying to track O, etc. we decided to BD every other day after AF ended. We did just that and at the end of January AF came. It lasted a week and seemed normal. I am very irregular so sometimes they are long, short, or come every other month. Fast forward two weeks after AF. Valentine's day I noticed I was bleeding again. Decided to take a test at home and it was positive. Of course I was really confused because I thought I had AF at the end of January and we had only BD after that on Feb 10, 11, and 13th. It was definitely too heavy to be implantation bleeding. Called OBGYN and she said go to the ER. Went to the ER on Feb 15th. Blood test came back positive with 578 hCG reading. Spotting continued and I got another blood test on Feb 17th which came back with a lower hCG reading. It was 530 down from 578. Doctor said likely miscarriage or chemical pregnancy. I've been bleeding since. No cramps just a constant flow. I haven't had blood work since either. Decided to test at home again on March 4th (nearly 3 weeks from first BFP) and it was positive. I'm really confused. I have blood work set up for next week. But has anyone had similar stories? I would have though the hCG would have been gone by now since its been 3 weeks and it was so low to begin with. Also, I haven't had any symptoms at all. Early on I felt nauseous, jittery, and tired but that all stopped. Sorry for the long post!