Sex if pregnant ?

Ok lady's idk if I am pregnant but my hubby and I DTD earlier and he said it felt like he was hitting a wall at the end of the tunal and was very tight is the cervix being low a sign of pregnancy? We have been TTC for about 3 years and had a miscarriage in 2012 at 12 weeks and im on my 3 round of clomid .. AF is due tomorrow .. Praying she don't show .. Any info helps thanks lady's ..