I Got The Depovera Shot In My Arm 2 Weeks

I got the depovera shot in my arm 2 weeks ago on the first day my period started. My period ended up being very light and I've been spotting ever since. My gyno said that I could do the implant, but needed to get the shot first, so I have the implant scheduled to go in next week. I have limited BC options because I am at high risk for DVT. I guess what I'm wondering is is it norm to have been spotting this entire time? Also, can I expect this to continue/get worse when I get the implant? Today the spotting is very dark colored, almost the color of dark poop, so that was also a bit alarming. I haven't had any other side affects as far as I can tell so far