Maybe baby?

Okay so I've had irregular periods pretty much since I was 15 but for the past few weeks ive been feeling tightness in my pelvic area and having cramps and pains in my ovaries. I have had an ectopic pregnancy before and 2 Miscarriages but everytime I found out I was pregnant was through blood test not urine. I guess my question is what are somethings I should know in order to know if I'm expecting?