serious pains and cramping

I'm 2 days under 12 weeks and for about 2/3 weeks I've been getting really bad shooting pains in the bottom of my back quite far to the left side, and inside my vagina and horrible cramps across my belly, I was bleeding really badly at 6 weeks and cramping but I had a u/s and the baby was still there, was scheduled for another 2 weeks later and I have my first midwife appointment in 2 weeks (my doctors are useless so I had a 5 week wait which leaves me at 13 weeks) and I didn't want to wait until then to bring it up but the doctors won't give me an appointment? I was wondering if anyone knew what this was? I've been bleeding on and off since I first started and the pain tends to worsen after sex?