Suggest Remedy For Irregularity In Periods

hi, i am sexually active girl age 25, i have my last periods started on 26 November ended on 1 December. i intercourse with my partner on 7 december after on ward on 9december i started to bleed again. it was very light spotting till a week. but from 23 december i start my normal periods. i just wanted to confirm that is there any need to get worried? i have already conducted my pregnancy test and that was negitive