Is my body just changing ?

These past few months has been weird for me . 1st month when I used the bathroom I thought af was coming but no . Didn't officially start until 2days later . Then the following month I was burning up(never happens) when af was on its way . Same thing af didn't start until the next day . Now this month after ovulation tingling boobs & kind of sensitive nipples (never happens) Af on its way . 1st day just a drop of blood next day a little more and third day af is here. Why am I having these weird new pms symptoms & why am I spotting. My periods used to just start now everything's changing and idk why .