2 months, nausea, cramping, tender breasts. Period last month. Cramping even when not near period. Tender breasts more sensitive this month. Causes?

Get checked out. It sounds like you have quite a few symptoms. In cases like this where there are multiple symptoms in different body systems it is usually best to see a doctor to begin the evaluation. If you think you might be pregnant check then check a home pregnancy test. They are cheap, reliable and available at any pharmacy.