Baby bean

Has anyone on here experienced this. I went in Friday for my check up. I was 35 weeks, 1 day. I've been measuring where I should have my entire pregnancy but now I'm measuring 3 weeks behind, I'm 1 cm dilated, and 70-80% effaced. We had a growth scan on the 6th and our little bean was 4 pounds and everything looked amazing and I was measuring right where I should've been. My doctor is saying either baby bean dropped real low or my uterus dropped. I'm freaking out because I had an easy first pregnancy and this is all new to me. Thank you