If you're still within the 72 hour window of having sex then you could get the morning after pill. However, if you're breastfeeding you can't take that because of the hormones. Also, if you're breastfeeding then it's unlikely you can pregnant yet anyway. You really need to be using condoms or another form of birth control right now. Your body hasn't healed properly, and won't for a few months so pregnancy so soon can be dangerous.