Need advice

I'm 27 I was supposed to start on the 11 of November and still nothing have been trying to get pregnant for months I have two children and one miscarriage a few months back we got a false positive and it just crushed us I am diabetic and on medication I figured it would help but I'm not sure if I should wait longer to take a test I've had back pains nausea loose of appetite I don't know what to do