I really need reassurance or help

So I don't usually do this but I really have no one else to talk to. I'm 21 years old with a fairly regular cycle. I was due the third of this month, got nothing but had all the signs of my period but add some nauseua in there. I recently found out that my boyfriend likes to practice the ill take the condom off for better pleasure for me when your not paying attention when I caught him twice. I took a pregnancy test the morning of sixth and it came back negative. Late that evening I began spotting really dark blood. This morning my period finally came but as for the flow its light and still early to tell. I can't be pregnant I just got accepted as a transfer student into Florida State. I don't know. Can I be pregnant? What do I do if I am? I can barely take care of myself let alone a kid. What do I do about my boyfriend he says he's sorry. But we've had the argument about protection multiple times before and I can't afford birth control at this moment and he just won't listen or understand, I don't know. I'm just stressed, and worried, and confused.