What Causes Severe Mood Swings And Extreme Tiredness?

Ok so for the past three weeks or ive been feeling really weird, ive been extremely tired, eating wayy more than usual, having some crazy mood swing, and ive also been a little bloated. The first thing that came to my mind was that i was pregnant so i took a pregnancy test and it came up negative. I waited after that and was still having all these symptoms. Yesterday my period finally came, two days late, at first it was super light which is weird for me but now it seems kind of normal but im still feeling the same as before plus all the symptome that go along with menstration. Is it possible at all that i am pregnant