Haven't had a period since August..irregular cycle test r negative>>been TTC since last month feeling diff?HLP?

Hi well i haven't had a period since August...I went to the doctor and my test was negative but now im getting really sick...ive been sleeping alot well feeling exhausted more to say and UM ive been sick on my stomach alot...i don't know what it is or what to do my period has been irregular and i Have been trying to conceive since last month...someone PLZ HELP!!!