Frequent Severe Abdominal Pain And Slight Vaginal Bleeding. Severe Abdominal Pain Soon After Intercourse. What Is Wrong?

In the last few months my girlfriend has had a number of problems now. It first started with severe abdomen pains and then she had slight vaginal bleeding. She had these pains for about a month or so but then they went for a while, however the abdomen pains and vaginal pains come back but not as frequent. After a few weeks they completely stopped and everything was alright. The pain was like a sharp shooting pain in her abdomen. Then a few weeks after we thought everything was fine but she started getting painful headaches. She kept getting the pains in her head but in different areas everytime. These headaches are currently still happening and recently we had intercourse and immediately after she had severe lower abdomenal pains and we both was extremely worried. They lasted for about 10 minutes and then went. She has been on the pill for over 6 months.