I noticed that anytime I have sex with my dh my cervix dilates to around 1 cm or so. I have checked my cervix ever since I had preterm labor with my last pregnancy. I discovered I was 3 cm dilated and 80% effaced at 28 weeks but I ended up delivering her at 37 weeks. I am thinking I have an incompetent cervix. Does this happen to anyone else? I go in for a pap smear next week so I will ask my obgyn but I am curious if this happens to anyone else. It occurs when I am not ovulating or near my period. I will be dilated for a whole day and the next day it will close back up.