Wa'alaikumassalam! Eh, this is something you really should check with your doctor ASAP, especially since your period hasn't come since November, banyak kemungkinan ni and kena confirm status dulu before any injection. A few of my mum friends went through this and they all had to get a checkup first to make sure everything's okay, sebab injection timing is important and kena tahu what's happening with your cycle. Jangan delay this one ah, better call your clinic and explain the situation so they can advise you properly, they won't judge, promise!