problems with cervix? ***TMI**

I'm on my period and I'm on the pill so technically it's my withdrawal bleed. But I had really bad cramps the first day and I checked my cervix and it's closed tightly. If I heave down like I'm pushing a baby, a little bit of the period blood comes out and relieves the pressure and pain I feel. I checked today again (day 2) and my cervix is still closed shut and feels very very swollen and is low down.