Not on birthcontrol, brown or bloody discharge, no pain

Okay! I've had a few sex partners but I've been with the same guy now for 4 years. I've always had a heavy heavy discharge to the point of soaking my underwear in a few hours and having to change them, but I used to it. But now, for probably 2 years now, I get off and on this thick brown yuckiness in my underwear and sometimes its redder and looks like blood. And after every period I get it really bad for about 3 days. But then it usually goes away for a while. And sometimes it never comes. But a few weeks ago my boyfriend and I had sex after a long time, and there was some blood on the condom. then since then I've had a brownish discharge. Sometimes red, sometimes brown, but everyday its there. I stuck my finger in there to find out what was up and I got period like clumps but they were darker. And this isnt a new occurance. It sometimes happened after my boyfriend and I had sex, but never lasted this long. I have no pain and no itching. I'm not on any birth control and my boyfriend and I always use condoms. We also usually use a lubricant but didn't this last time. I'm really conscerned because my mom had endometriosis and cervical cancer, but I'm a non-working musician and I don't have money at all to get checked out. I mean I'm broke. And I can't seem to find any answers for a person who has the brown discharge and isn't on some kind of birth control. Some other details that might help: I have a very short and very painful period. It lasts for about 4 days and I usually spend 2 or 3 days in bed and I take about 3 or 4 liquid advil every 3 hours. I also get cramps very bad through my back and all the way through my hips down into my knees. Sometimes but very rarely the pain will get so overwhelming I throw up or black out, but not often. There are some positions I find are very painful for my boyfriend and I. Doggystyle for example causes me a lot of discomfort. hes not huge or anything, only about 6 inches, but it still hurts. My periods occour about every 20-24 days, a little more often than most I know. My boyfriend had only had one sexual partner, me, and I've had some, but everyone of them I was protected. I don't do the unprotected sex thing. And I only sleep with people I know and that was over 4 years ago and I still talk to all of them and I know they have no diseases. OH! And sometimes I'll just masturbate with stimulation to my clitoris and then I'll hve the bloody or brownish discharge as well. If its bloody its usually clear with a little blood versus the brown which tends to be heavier and have some climps in it, but also not always. I hope someone can help me because this is the only advice I can get. thanks.