TMI: not sure what I saw

My period was over a month late and even though I used to have irregular periods and then they started becoming regular for a long time I didn't think anything of it. The one time we had unprotected sex he pulled out. I usually have clots during my period but I was having excruciating cramps and I saw something come out that didn't look like a clot at all. It actually looked like it was a little clear like it could've been an amniotic sac. That's really the only thing I can think that it would be. What are the chances though? Idk it's really worrying me but since it already came out I don't think the doctors would be able to tell me anything...