KIBBLES,
Not sure if you're taking about supplements or just the hormone in general. If your progesterone is HIGH and stays high like it should if your pregnant you would NOT get your period. That's why they do progestin/progesterone supplements for women who have a short post ovulation phase as their progesterone on its own drops too quickly for implantation or is insufficient to sustain a pregnancy and drops causing a period and early miscarriage. When your progesterone drops your period starts. I do believe that most women I've seen write on here who are using synthetic progesterone say that in general it doesn't interfere with them getting AF. However I'm not sure if they are only told to take it x number of days etc. If that's your question I would ask your doc. Good luck!
Looks like they are similar, but that a progestin is synthetic and produced in a lab.
AF = Aunt Flow (Period).
I was on a progestin for 10 days (aygestin 10 mg) to regulate AF. I hadn't had a period after being on Lupron for endometriosis. After the 10 days, I got AF after 2 days... now it's time for Clomid.
After looking online, I'm trying to figure out the difference between progesterone and a progestin.