I had my Implanon birth control implant removed 4 days ago, had sex the day after, and my partner ejaculated inside. Just this afternoon (3 days since the sex) I started having a light brown discharge and very mild cramps, wondered if it was implantation bleeding.. Could I be pregnant? I am trying to conceive.

There is no way to know for sure either way at this point. It could be implantation, it could be your body adjusting, or a million other things. I know, not what you want to hear when you're trying to conceive. You'll have to wait and see. Best of luck.

Firstly, there is no scientific evidence to prove implantation bleeding. Secondly, it would be too soon for implantation to occur since it takes as many as 3 - 5 days for the sperm to reach the egg in the fallopian tube and then travel another 3-5 days back down to the uterus.

Most likely your body is withdrawing from the constant hormones provided by the implanon, therefore you are bleeding. It may be several months before you get back to a regular cycle.