I had a failed cycle of ivf. Drug with drawal bleed was 67 days ago and not had a period since. Neg pregnant test. How can I start cycle again?

Start cycle. I would have you take a vaginal sonogram to r/o preg. And check endometrial thickness.. Depending upon the thickness you may need estrogen stimulation prior to Provera (medroxyprogesterone) to cause a withdrawal bleed. When preg is r/o and endometrium is thin you can start a stimulated cycle.
I wouldn't... If/when we have a patient fail an ivf cycle, we sit down face-to-face to review why it likely didn't work so that we can try to make it better if the patient tries again. Also, prior to another ivf cycle, it's important to have baseline blood and ultrasound testing to determine if there are enlarged ovaries, cysts, hormones still at a level that would preclude starting again, etc. Etc.