Since my last period I had unprotected sex as we are trying to conceive. Few days after I started feeling nausea and heavy feeling in my tummy... Now my period is 2 days over m having back pain, nausea, craving sweets I haven't eaten for years, and sudden tummy bulging big, tired and sleepy at daytime, having difficulty sleeping at night, discomfort... The question is could I be pregnant? I had cystic ovaries before but last period was very heavy with clots and veins...

It would be too early for you to have pregnancy symptoms just 2 days late for your period. You wouldn't have a pregnancy belly until about 16-20 weeks of pregnancy.

Premenstrual symptoms and pregnancy symptoms are almost identical. You will have to wait until you are 2 weeks late then test using first morning urine.