I hadn't even thought of the b/f issue!!!!
Does the worry ever stop?
The manufacturers site say there is no problem, and I found this:
Progestin-only contraceptives are the preferred choice for breastfeeding mothers when something hormonal is desired or necessary. Some moms have noticed that even these type of birth control pills adversely affect their milk supplies, so if you choose this method you still need to proceed with some caution. Keep in mind that progestin-only contraceptives come in several different forms; ie. the Progestin-Only Pill (POP) also called the "mini-pill" (Micronor, NOR-QD, Ovrette, Microval, etc), the Depo Provera shot, the progesterone-releasing IUD (Mirena, Progestasert) and the Norplant implant.
For MOST moms progestin-only forms of contraception do not cause problems with milk supply if started after the 6th-8th week postpartum and if given at normal doses. However, there are many reports (most anecdotal but nevertheless worth paying attention to) that some women do experience supply problems with these pills. Only at higher doses than normal can this type of pill affect the content of breastmilk. At these higher doses it has been shown to decrease the protein/nitrogen and lactose content of the milk. At higher doses it may also suppress milk supply, perhaps causing slow weight gain in the infant. At regular doses, this does not seem to be as likely.
If you're interested in one of the longer lasting progesterone-only forms of birth control (the Depo-Provera shot lasts at least 12 weeks (but effects may be seen up to a year); the Mirena/Progestasert IUD and the Norplant implant can last up to 5 years), it is a good idea to do a trial of progesterone-only pills (mini-pill) for a month or more before deciding on the longer-term form of birth control. If you find that you are among the women whose supply drops significantly due to progesterone-only birth control, you can simply discontinue the pills - rather than struggling with low milk supply for several months until the shot wears off or you get the implant or IUD removed. Do note that the Mirena/Progestasert IUD delivers its hormone directly to the lining of the uterus, which only leads to a slight increase in progesterone levels in the blood stream (much lower than that found with the progesterone-only pill). As a result, there is much less chance of side effects from the progesterone than from the Depo-Provera shot or mini-pill.
I guess if there is no extra risk from the hormone, then the perforation risk must be the same either way.