Help me

I've only had 2 periods in my life, but it's been 61 days apart. Now I'm on day 64 of my cycle but I can't be pregnant. I've had discharge with a bit of blood in it 4 times, I don't think my body would consider that a period since I have a very heavy flow. I've had all my PMS symptoms such as cramps, backache, headache, tired. My cervix is high and hard and I'm taking black cohosh for my irregular periods. Should I stop taking it? Can anyone tell me what's going on?