I have been on tri-sprintec for six years now. I am very good about taking my pill on time. I had one hiccup last month which was that a pill broke in half when I was trying to get it out of the pill pack. I called my pharmacist and they said to just take both halves and it should be fine. I had sex on Jan 29th (placebo week) and used the pull out method as well. On Jan 31st, I started a normal five day withdrawal bleed right on time. It was the length and heaviness as always (five days, filling a few regular tampons a day.) I assumed everything was fine and I was not pregnant. Then, starting around Feb 17th, I started to have breast pain. My breasts are still tender now. I also had occasional nausea. Could I be pregnant even though I had a normal five day withdrawal bleed last month and haven't had sex since? Basically, could the bleeding just have occurred because implantation did not happen yet and pregnancy hormones were not high enough yet?