Period + sex

Hi guys, bit shy but I just had sex and i kinda started my period this morning but the bleeding has been like spotting ..been having cramps etc but usually my bleeding would have been heavy by now as has been heavy ever since having my daughter ...it was a heat of the moment kinda thing and we didn't use any protection as never have ever used a condom so now I'm just worried incase Ill get pregnant ... I don't want to use a morning after pill as never have used one and also kinda don't agree with using it ...what should I do ?