If you have always had regular monthly cycles, you should have had some sort of investigation to see why you did not have a period for three months. If you finally had a normal period with normal flow, that should rule out any pregnancy
even if you are sexually active. Your symptoms point to some hormonal
disturbance as well as general ailment. Please get a trans-vaginal sonogram that excludes/confirms a pregnancy in addition to helping in understanding local pathology, if any. Also see a general physician and a gynecologist for further management. Hope this helps.