What could this possibly be?

I am a little confused. I shouldn’t be feeling like I do, because I just had my period on the 2nd. It was light and about 3 days. My still hurt and my are sore (they never feel this way after my period. It always goes away right about when I start), and I feel like from time and time I could just throw up. I am having weird twinge/pains in my lower abdomen, but only here and there, and I am sooo tired (I never want to wake up in the morning). I just feel kinda blah. I don’t know what it could be. I’m not pregnant because I just had my period. What else could be wrong with me feeling this way? Anyone else have this happen after their period? What could it be?