Early menstral/period, no cramping just side pains, loss of apetite, running fever.Could I be prego?

:$ I AM A 20 YEAR OLD FEMALE. I HAD MY LAST MENSTRAL ON APRIL 1, 07. I WAS ON TIME AND NO PROBLEMS. LAST SATURDAY WHICH WAS 4/21 I STARTED BLEEDING DURING INTERCOURSE WITH MY BOYFRIEND. I THOUGHT I HAD STARTED MY CYCLE, BUT I DIDNT EVEN BLEED FOR A WHOLE DAY. WASNT NORMAL FOR ME. I HAVE NOT BEEN FEELING WELL FOR THE PAST FEW WEEKS. I HAVE NOT BEEN SICK, BUT HAVE LOSS OF APETITE, RUNNING FEVER ON AND OFF, FEELING TIRED AND DRAINED, NOT CRAMPING BUT A PAIN IN MY SIDES A FEW TIMES A DAY. MY BREAST AND NIPPLES HAVE BEEN VERY TENDER THE PAST FEW WEEKS AS WELL. LAST NIGHT I WOKE UP AT 3 IN THE MORNING DUE TO SUCH A BAD BACK PAIN, ONLY TO FIND OUT THAT I STARTED MY CYCLE. NOT AS HEAVY OR THICK AS USUAL. LIGHTER AND THINNER. I HAVE BEEN PREGNANT ONCE BEFORE AND LOST THE BABY. I WAS SIX WEEKS WHEN I FOUND OUT BUT HAD MY PERIOD THAT MONTH. COULD I POSSIBLY BE PREGNANT? PLEASE SOMEONE LEAVE ANSWER OR ADVICE FOR ME.