Newbie help

Hi! Only my second month charting temperature, though my 10th month ttc. I have endometriosis. Last month my temps were all over the place and ovulation was never detected. This time things were looking good. I tested 10 dpo and 12 dpo. Both negative. I keep thinking AF will start, because of cramping. Now I’m a couple days late, but when my temp dropped I was sure I was out this month. But does it mean anything that it’s going up again? I ran out of tests and haven’t had time to buy again, but will tomorrow. However, every month I tend to be late and I test and it’s always negative.😭