I’m on the pill but I may have missed a day last month. I had sex once during what would be my estimated fertile window. I am now 11 days late for my period. No spotting or anything. I’ve taken 4 HPT all came back negative but I’ve been extremely nauseous and had a lot of cramps. I’ve been getting tired quickly and feel lightheaded or out of breath often. Is it possible I could be pregnant even with 4 negative tests? Should I get a blood test?