Snowlover

I'm a concerned boyfriend! Please help! I've been dating my girlfriend now for 4 months. She claims that she has been on Estrostep Fe since the first of June. I know that she has missed a pill here or there in the past, and she has been upfront about it, so we have used a Condom. She has told me that since the pack she started the first of September, she hasn't missed a pill. The problem is this, she claims that here cycle has always been messed up. She was on the shot b4 we met, and didn't get her period, but she claims she gained too much weight and she switched to the pill. Now i'll get to the problem, her period has not been regular at all, and it makes me nervous. We stopped using a condom a few weeks ago, and I want to make sure we are safe. We don't want to get pregnant. On her last pack of pills in October, she bled in her second week for a couple of days. Was this her period coming early since her cycle is always screwed up, or just a bleeding side affect? When she got to the brown pills, she got her perio, (i guess), for one day on, one day off, for about the extent of the brown pills. Should I be worried? Can the irregular period cancel out the effectiveness of the pills? Also, she's breaking out, and is very moody. She complains of being sick to her stomach all the time, and gets sore breasts a week or so b4 the brown pills. Help Please!