Suggest Remedy For Back Pain

Hi I am 29 years old,about 54cm tall and weigh 72kg. I have been on the 2 month family planning injection for 8 months, meaning I took the injection four times. I then stopped because I wanted to fall pregnant again. My menstrual cycle is not yet back, but I would like to know the possibility of falling pregnant before my periods are back. Lately I have also been experiencing back pain and something like period pains but I haven't spotted. It is normal for someone who has stopped taking the injection. Please help me