Hello, and i hope I can help you today.
If you have gotten your depo shot within the last three months, especially if you have been on it for at least 6 months, you do not have to worry about
pregnancy even if you have unprotected sex. The Depo
Provera injection is nearly 100 percent effective in preventing pregnancy, and many of the side effects you mention, like
headaches, moodiness, appetite changes and cramps, can be caused by the medication itself and do not indicate pregnancy.
Another condition that can cause back and
pelvic pain, especially with cramps, is a
urinary tract infection or
vaginal infection, which can happen when having unprotected sex. I suggest you see a GYN doctor for an evaluation of your urine and to check for bladder or vaginal infections, but again, if you are up to date on your shot, then you do not have to worry about pregnancy. You certainly can perform a urine pregnancy test anytime, but I doubt you could be pregnant unless you have not had your shot within the last 3 months.
I hope I was able to adequately answer your question today and that my advice was helpful.
Best wishes,
Dr. Brown