not sure what to think

So I've been feeling sick for 2 to 3 days now.. nausea (all day and night) with occasional vomiting. Lower back pain and cramps (hurts a little more then regular period cramps) and my boobs hurt really bad I can barely touch them... has anyone had these symptoms before and if u have do u know what it is? Never been sick like this before:/ I've been trying to conceive but I don't know if it's pregnancy or not.