My boyfriend and I almost always have protected sex, however one night about three weeks ago, we didn't have protected sex. I have been on Orsythia for about 4 months now, and have taken it every day (maybe not at the exact same time everyday, but usually MAYBE 3 hours difference at most. I take it in the morning usually when I get up.) However, I am about 5 days late and am starting to become concerned. Again we are always safe and he says that everything was okay that night; however I'm beginning to grow concerned. Also, about 2 months ago, I just didn't have a period at all and I was on Orsythia. Is it possible to just not have a period sometimes, is it maybe because I am stressing about it also? My breasts are tender, and I'm moody and a little tired with some slight cramps like usual, I'm just not bleeding. Help, does this kind of thing happen?