pregnant after birth?

Me and my husband were talking about having another baby so our son can have a sibling close in age. I gave birth march 10 no complications, no stitches and no tears! after i gave birth i bled for about 1 1/2 weeks. Went from light red to light brown. My husband and I had sex april 1st and of course he came inside not alot since i gave him oral almost everyday and he came alot over the last few weeks. He came inside a little again a week later. I took a pregnancy test last week Sunday and it was negative. The next day i started bleeding. So im guessing this is my period it's light brown right now but i was wondering has anyone gotten pregnant after birth and had a period still or should we try again.