First coitus. Period to visit doctor?

I had coitus for the first time & it was very painful & I bled a little at first. After 30min i started bleeding profusely( first light red blood then brownish period like blood) & the flow was so much that sanitary napkins couldn't even control it & i started feeling weak(this continued for 3hrs) then continued a little for next day & in drops for next few days. No pain internal or external. This happened 10 days before period due date. Did i get my period early due to hymen breakage? Do i need to get checked by a doctor or is this normal, i should get rest and it'll heal naturally? From 20 days before this incident I started taking Bycalvit, Intabion-L, vit A. Did this have any effect on the situation? Also no precaution was used during coitus( it was just for a minute & no ejaculation was there) should i be worried? How to eliminate the possibility of pregnancy here? Suggest medicines if needed. Should i wait for next period to visit doctor?