Odd cycle letrozole. Confused helppp!!

So the 28th of Jan 2021 I had spotting thought it was my period. Called doctor so he could fill my first month of letrozole. Well the spotting stopped so I took pregnancy test. All negative obviously ( I never ovulated last month so it wasn’t surprising) I waited to the 1st of February it was a Monday so I had to wait the weekend for doctor to call me back. Anyways he said he was taking that as period and to take letrozole. And to still follow up with my ultrasound the following Monday so I did. I was taking opk every day all negative until Friday I got a postive opk, Saturday I didn’t take one. I took one Sunday night postive. So I went to the ultrasound apt. And it looked like a follicle burst. Free fluid around it. There thinking I did already ovulate. That means I ovulated 2-3 days after letrozole if that’s the case anyone else experience this? Did I baby dance enough? Is it possible to ovulate this early? I’m confused. Both opks I took today are negative