I need help

Krystal

I have been trying to have another baby I have four but I have been trying since last August. I got a positive pregnancy test this past May and before May could end I miscarried and now it’s August and I’m still trying and I’m 40!!! Can a woman be pregnant on her period because I’m on my period now and it started Wednesday night and it’s been mild not to heavy but I have cramps and my lower back has been hurting so bad for five days can anybody help