Advice needed urgent!

Patient: Im 26 years old. Had a miscarriage about 8 weeks ago and went on the petogen 3 months injection the day after my miscarriage. Its the 1st time im on the injection, i went on it because i was bleeding alot. But i feel ready now to try again for a baby….i never got my period though just been spotting most of the time. Wud like to know if i cud get pregnant or ovulate through the injection? or can u reverse the injection? if not about how long before i cud concieve? i must go back on the 21 st of october for my 2nd shot but im not going to. thanx any help wud be apreciated