Hello. I have been taking tamoxifen since July and I have had a couple of months when I have had irregular bleeding. Of course I went into immediate panic and starting ringing all the medical people I could think of. I had to come off the pill when I found out I had BC so my body is still wondering what the hell is going on! I have just been for a scan to check that my uterus is ok, and the doctors are really happy that it is a side effect of the drugs and change from the pill, but they're going to do a hysteroscopy just to be sure. I can't fault the care and attention I have had from the NHS staff. Some people are reacting differently to this drug, but the thing is to try not to panic because it really is quite likely your body is just adjusting. One thing the gynaecologist said yesterday was that radiotherapy can interfere with your ovaries as well so don't be surprised if you get some irregular bleeding again after you have finished treatment. Just keep on top of things and get things checked out but try not to go into a blind panic. You are on their radar now and they will keep you right! Happy New Year.