After A Depo Shot, Can I Be Pregnant?

Hello. I`ve put a call in to my doctor but in the mean time I would like some feed back from you...
I`ve been on the depo shot, off the shot, became pregnant, opted for an abortion. I wasn`t very smart & had unprotected sex again before reecieving another shot.
I went to the Doctor right after unprotected sex, had the pregnancy test done which came out negative & they gave me the depo shot. Well, last evening my boyfriend and I were about to make love when he went to my breasts & said that they were lactating. I wasn`t sure what to think, but I took my breast, squeezed my nipple and sure enough a little bit of fluid came out. I`m uneducated about this form of birth control. & decided that if I was ever to become pregant again that I would not use an abortion as a form of birth control. My next appointment for a shot is in Oct. I wonder if you have known anyone to have been pregant & had a healthy child after this injection. Or if you know that it will kill the fetus/embryo?Since the pregnancy test took showed negative when it could have been positve. Please advise as I patiently wait for my Doctor to call.