Trying to conceive

I have been off birthcontrol for 4 months going on 5 months now and have been trying to conceive but still nothing and my period has been irregular so I would be very confused on when I can get pregnant my last few periods has only lasted 3 days or less and this has been the after effect of the removal for nexplanon I'm really trying to conceive but its seems I have no hope maybe my body is still trying to regulate I'm starting to get depressed because the doctor didn tell me it would be this hard to become fertile after my birth control removal 🤦‍♀️