Conception after Depo

I haven't had a period in 2 yrs because of Depo. After being off the shot since July, I was inactive with sex for 5 months and after the first time. My period came on on two days later, so light I though it was implantation. Here we are less than 2 weeks later I had spotting(light pink, only when I wiped for 1.5- 2 days) and my period isnt due for 7 more days(10days before expected period at the time). Has anyone had this happen and was actually pregnant?