What Causes Tiredness Prior To Every Menstruation?

i feel tired and sleepy, its rainning here. Recently i had irregular periods. From 24 may to 5 june my husband was with me, he stays with me only for 15 days in a year. this is going on from past 6yrs. I have a cycle of 27 days usualy rarely during hot season or heavy work cycle is 26,25. periods are normal i have slight abd pain. my last periods were on 24may, But recently i had symptoms of preg like, tiredness,pain in breast,frequently eating,headache then i got periods on 17june and symptoms disappeared except tiredness. cycle was of 23days, felt strange,still i thought i might be preg i waited.. i got next period on 12july 25 day cycle, still have tiredness, i took a home preg test, result was nega, what is it that is making me tired should i wait for another month or is over thinking abt preg , help me