Could I be pregnant?

Okay so, I'm really unorganized when it comes to my cycle. I haven't had a period in 3 years due to the BC I was on for my blood disorder. I got it removed about a month ago and still haven't gotten my period. I'm not sure when I'm ovulating or anything like that. About 4 weeks ago I had unprotected sex with my boyfriend of 3 years and he finished inside me. For the last week and a half. I've been having these problems... severe cramping when walking, fatigue, nausea, crazy mood swings, lower back pain, constipation, heartbdurn, headaches, frequent trips to the bathroom, and hot flashes. Could I be pregnant? Should I take a test?