My period was dues sept 25 and it just now starting oct 4. Prior to it starting today, I ve experienced headache, fatigue, gas, cramps, bloating , frequent urination and loss of appetite. Took a hpt Tuesday oct 2 and it was negative. For the pass two days which includes today, my bbt was 97.68 oct 3 and 97.71 oct 4(today). My period has been on point every month so it was strange to be 9 days late. What could be the cause of this?