I would get checked for peace of mind. I did that at 15 weeks and actually read that when u lay on ur belly ur body will feel pain before u have time to cause it to ur baby. So it could just be ur body's way of saying don't do that. I would still let ur midwife know just in case that's what I did
I'm 26 weeks and lay on my tummy a lot still. I don't think you did but it wouldn't hurt to go get checked, go with your gut feeling.