Period while on active pills.

Jade • Senior in college by day, full-time musician by night.
Help!
This has happened once before (back in May). I was on my regular period during the 4th week of my bc pack (the placebo pills) and it lasted normally. It usually starts the Wednesday into that week and lasts until Sunday when I start the new pack. I started the new pack, but that Friday (almost a week later) I started a heavy full-on period out of nowhere. This period lasted 24 FREAKING DAYS. I called my doctor several times (I live in OK for college but have insurance through Kaiser Permenete in CA which is a private HMO that no one takes here) she told me not to worry and that it was probably due to the fact that I was in a new relationship and having more sex than I ever have before... So I decided to not worry about it.. It ended, and never happened again. I was in CA this summer to see my doctors and asked her about changing my contraceptive because it had still frightened me. She ensured me that there was nothing to worry about and instead of giving me something new, told me to take 3 packs back to back (without the placebo week) to make it where I only have 4 periods a year. WELL. I am currently 10 days into the 3rd month of pills back to back like she prescribed, and this last Saturday (6 days into the new pack of bc) started another period out of the blue. I'm still taking the pill everyday because I'm afraid if I stop I'll mess up my whole body. This period was semi-heavy from Saturday-Monday, light Tuesday morning, and then seemed to go away all together. I was elated! My boyfriend and I had sex that night, and yesterday morning. Then, after Breakfast yesterday I used the restroom and it was back with a vengeance. I freaked out a bit, tried calling my doctor (who STILL hasn't returned my calls) and then it seemed to go away again. Like maybe it was a false alarm... All day yesterday (after the freak out and "false alarm") it was completed gone! Nothing! Even through the night until this morning. Then again, after breakfast, went to the bathroom and it's back again. I'm freaked out. I understand that the first time it happened (May) was probably my body adjusting to the amount of sex I was having, but this time I feel like it could be something more serious... The cramps and headaches are constant which for me is abnormal in itself.... My only option here in Oklahoma is to go to the ER, but I don't have $1000+ to go there if they won't even examine me because I'm still bleeding.... Any advice? Anyone who has had similar things happen? My boyfriend doesn't understand why I'm freaking out, but as a girl who knows my body this is very out of the ordinary and I don't know where to go from here. I am also having a major surgery in 2.5 weeks and I'm worried they won't operate on me if I'm on my period...