Women's Health Community

Dear LadyOdd: Simply stated, if the uterine lining is like grass or lawn, estrogen is like the fertilizer (causes a thickening of the lining ), and progesterone is like the lawnmower (keeps the lining thin by three different mechanisms). This is why DepoProvera (high dose synthetic progesterone in a shot form) brings about a thin lining, and why birth control pills (relatively progesterone dominant) bring about shorter, lighter periods. It is also why women who miss ovulations (no progesterone produced) are at a greater risk for too thick lining.

The usual dose for trying to "kick start" a period is Provera 10 mg for five days. That is enough synthetic progesterone to trigger the lining to shed--usually about 72 hours after taking the last Provera pill. In your specific case it sounds like you have been using two Provera pills (possibly 20 mg daily) for 14 days every month. That MIGHT be enough lawn-mower activity to give you a very thin uterine lining such that there is not much up inside to shed. It has been estimated that the DepoProvera injection supplies as much synthetic progesterone as 20 mg of daily Provera pills.

Of course you should definitely rule out an undetected pregnancy as the cause of your missed flow. If you have conceived the Provera should not be taken. I

Your best bet is to see a GYN or even your local county family planning clinic for the most "for sure" answer. They can do a reliable pregnancy test at the same visit. As an aside, it is not a problem to miss a flow if the reason is a thin lining. Many women on DepoProvera, birth control pills, Mirena IUD, etc.have flows which get lighter and lighter then disappear while the medication is being used.

Yours,
Jane