6 weeks after?

gave birth 6 weeks ago to a beautiful little boy. I had no problems, no episiotimy or tears or anything. My husband and i have been having for a few weeks now and obviously we are using condoms, mymidwife wouldnt give me any birth control until my 6 week check up. BTW my midwife said that we could resume ual activity when my bleeding stopped so its not that i didnt listen to my midwifes advice. I have been having cramp like twinges in my lower tummy. I was wondering what these are? could i have an infection or something or are these normal? also when is the normal time to get your first period. I fed for the first month but since I had to go on a medication for a very severe skin disorder I was not able to feed anymore since the medication would get into themilk and make our son sick. So i am not feeding anymore so when will I get my first period? thanks, if anyone has a clue whats going on or went through the same thing i would appreciate advice!