Suggest Treatment To Get Normal Periods

i had sex with my partner on 28th jan n my mestrual date was due at 30 jan.(i have regular periods)his sperms did not enter my vagina bt i didnt have my date on 30th.then ther was some spotting on 1st feb and 2nd..bt no proper bleeding..i did a pregnancy test yesterday it ws negative..now i m having bleeding again but not proper..i need my date to come properly..wat shud i do to have proper and heavy bleeding