I have been on my menstrual cycle for over a month, now found out I am pregnant?

I have been on my menstrual cycle for over a month closer to 2 months. I found out I’m pregnant less then a week ago… I bleeding heavy and have abdominal cramps and started getting headaches. (…) I’ve smoked meth 6 months ago and drank GHB around same time. I’ve been an addict for 10 years and I’m 32yo. I’m afraid it could be cancer or a cyst and the pregnancy test is not accurate. Please advise?