Question??

Hey everyone I've got a ?? If anyone can give me advice I'd greatly appreciate it. Ok so my last period was june13-18 2015 spotting mostly but after I got off I've been cramping in lower abdomen and lower back been nausea boobs very very sore hungry but feel sick I took a test in June but neg. I'm suppose to start july 20th but today which is july 16th when I wiped had little blood. So if not preggo why is boobs hurting and been cramping all that?? Has me worried. If anyone cld give me any advice I'd greatly appreciate it. Have dr. Appt. on the 30th.