Terrified! Update!

So I had my first ultrasound appointment Monday the 6. We didn’t see much. I go back on the 20th for another one. I have had really long cycles since January. I have done a lot of research and found that I may have implanted later than I thought. I got my bfp on April 11. Going by what I’ve researched I would have implanted on or around the 5-6 of April. My doctor has me on progesterone. Had anyone experienced this? I’m so lost and confused.

Update: I had my second ultrasound may 20th. The baby has grown some. I go back on June 6th for my 3rd ultrasound. To make sure baby is still growing. I thought I could see a little flicker of the heartbeat. But doc did it so fast I couldn’t tell for sure. I am tired of this waiting game. I