Hi, I'm 24 Yrs Old, I Recently Had Few Extra

Hi, I'm 24 yrs old, I recently had few extra antibiotics and painkilles, 4-5 days after which I had vaginal bleeding. I had my last periods on 30the which were late by 3 ands and lasted just for 2 days, the blood flow was also daily less as compared to normal. I'm worried about the spotting..plz let me know of the reason. Do I need a check up?