So... I have been putting this problem off for a while and I think I am going to kick myself in the ass for it because I am worried it may be really serious...

A month or so ago I started getting lower back pain that has gradually gotten worse and for the past few months I have been experiencing cramping after sex with my boyfriend. I thought this was normal until for the third time in a 2-3 month span I have spotted after having sex... 

I have no other symptoms other than being maybe slightly emotional and tired. I did take a pregnancy test I believe at the end of November after my period and it was a big fat negative. The cramping after sex and spotting happened once before this test. I am on birth control pills as my main choice of protection, also backed up with withdrawal, and then condoms during my fertile week. I also have pain during sex as well, almost like he is hitting something inside. Happens more often than not and worse at other times during my cycle and I know he could be hitting my cervix? Right? I don't know. 

I am calling my doctor tomorrow for an appointment meant, I am due for a Pap test as well, so hoping to have that set up too. 

My boyfriend and I had sex earlier tonight around 7:00 pm, and noticed the blood at 8:00 pm, but I have been cramping since after sex. There was pain during sex as well as described above but it is just so uncomfortable... 

Any idea as to what could be going on with me? What questions should I and can I ask the doctor? Should I take another test?