Brain fart..

I know this is long, but please help me lol I literally can not remember having a period in January. I know for sure I had one in December because it was just ending as we were leaving for our Florida Vacation. Jan AF *should’ve* been here 14th-20th, however I have it recorded in my app DH and I did the deed on the couch on the 19th, which I would not have done had I been on my period. I got a positive test on 2/26 when Feb AF would have been 11days late. The First Response test was super faint, clear blue said pregnant. If I was 11 days late, shouldn’t my pink line test have been darker? I know you can ovulate later and blah blah, but I usually track this pretty closely as we had been trying since September 2018. We had decided after vacation to stop trying because if upcoming events and I teach preschool, so having a baby in the middle of the year isn’t ideal. I recently read about a “hook effect”? Once you’re so far along a test will show faint or negative because levels are too high? Do you think this is what could’ve happened to me? I would’ve potentially been 9weeks when I tested. As of right now, going by my mysterious Jan AF on Jan 14th, I’m 7 weeks due 10/21. First prenatal appointment not until 3/21. How do I retrace my steps to find out if I really didn’t have a period in January because waiting two weeks to find out is going to drive me nuts!!