Hi, my regular period started on January 6th, on Jan 18th I began to bleed again, medium flow which lasted four days. My breast have been sore for a couple of weeks now. Based on a 28 day cycle my next period should have started February 4th, but I haven t gotten it yet. Is it possible that I may be pregnant and the bleeding that occured on the 18th was Implentation bleeding. One more thing I want to add is that after my reg. period I took my pills for a couple of days then stopped, so is it possible that it could have cause me to get my period alot sooner and I actually got my period again on the 18th? I hope I gave enough information. Thanks