About two weeks ago my boyfriend and I had sex. We tried anal and it hurt too much for me so he pulled out then stuck it in my vagina. I yelled at him afterwards and showered washing down there very well. Now I'm having lower back pain and cramping where period cramps normally are. My period hasn't started yet and it's either late or I miscaluated when I am suppose to start. I've taken to pregnancy test five days apart, both negative. I've been stressed out a lot too about some things. Any advice is appreciated.