I know for a fact my last period started 12/09

I know for a fact my SO and I had sex December 23 before he left town and not again until I met him couple weeks later on January 7th

On the day of the 7th I had brown spotting, so I took an HPT and got a veryyyyyyyyy faint line. So faint he thought I was imagining it.

On the 9th my pregnancy was confirmed by doctors.

HOW IS IT, that last week at 6 weeks 5 days there was no fetal pole and I was measuring less than 5 weeks. Threatened miscarriage

Today at supposed 8 weeks I am measuring 6 weeks and there is a baby in there with a heartbeat

HOW AM I TWO WEEKS BEHIND SCHEDULE AND EVERYTHING I’m being told by doctor is that everything seems to be progressing perfectly fine?!!!

My only guesses are that I ovulated later than I thought. I thought it was on Christmas Day, using OPK’s.......and that implantation took forever.

I really don’t know what to think even my SO is looking at me crazy 😩😩😩😩 doc said I must have conceived in January but that’s literally impossible