i was feeling sick for a(1) day about 3 weeks ago. then i started to get really moody and irritated a few days later(that lasted for a week or so). my breasts then began to be sore to the touch(which has lasted for a about 2 weeks now and still going). and during those same 2 weeks. i had slight bleeding. it only lasted for a day. not heavy enough for a tampon on menstrual pad. so i thought maybe it was implantation bleeding. however i just started my cycle today(right on time). is it normal for these things to happen, and not be pregnant because i started my cycle??? is it possible to experience implantation bleeding, and STILL have a regular flow menstrual cycle afterwards???