Rape. Where is the fine line?

I keep hearing people talk about rape. I have been a victim in the past, and I was raped because he thought I would take him back if he had sex with me. I didn't know it was rape because it was for the purpose of "love". Another times, another ex continued thrusting even though I insisted that he stops. He only stopped when I mentioned that he was having sex with me against my will. So my question is, when is it rape? And has anyone else been in similar situations? Or am I the only one with bad luck.

Cheers!