... about 11 weeks after my last shot. The 15th week after, I had what I believe was my first period, very heavy/clots and cramps for 5 days, normal period symptoms. I'm now 17 weeks after last shot and having LOTS of CM for several days now... is this likely a side effect of stopping the shot or am I ovulating for the first time since? The amount of CM is much more than I've ever had and I've been told most people don't become fertile this quickly. P.S I also stopped breastfeeding around the same time of my last shot