My girlfriend told me about this because she gets blood clots from hormonal birth control and we wish this was an option today.
You should complete this survey like I did if you are interested: http://www.surveymonkey.com/s/TSKSKGM
You should complete this survey like I did if you are interested: http://www.surveymonkey.com/s/TSKSKGM
This means that during that time, you don't need any condoms or anything.
Unfortunately, while being extremely well-researched in Germany for more than 30 years, it is quite uncommon in the US and only known as "Fertility Awareness", which is not the "pure" symptothermal method. The method is oftentimes associated (wrongly) with Christian groups.
You can check out Wikipedia:
http://en.wikipedia.org/wiki/Fertility_awareness
Edit: Perfect use application of the "pure" symptothermal method has a Pearl Index of 0.4 (99.6% effectiveness) and typical use is 1-3 (97-99%). This is quite comparable to the pill.
(There are only two real risks/side effects: Heavier bleeding, and it's important not to get Pelvic Inflammatory Disease (which is another way of saying, it's even more important than normal not to get STDs. If she can handle the first, and is in a monogamous relationship - or at least, always uses condoms with people who aren't guaranteed STD free - then neither issue is severe.)
Mind you, vasalgel sounds even better to me. :)
Blood clots, heart problems, cancer, bone loss, and sun sensitivity are all associated with estrogen-containing birth controls. From my research, progestin-only methods don't have those drawbacks.
As always, IANAD and this is not medical advice, but you should talk to one.
My girlfirend reacted very badly to a well-known and tested brand, however she seems to do much better with a local-brand product with different composition (started that one a few months ago).