Hi L.,
Break-Thur bleeding is never fun, but it happens to most women, sometime in their lives.
I experienced it while I was taking Yasmin as well as a couple others. It wasn't until about 2 years ago, when I found Loestrin 24 that my periods became regular, lighter, shorter, and no break-Thur bleeding. Also, the PMS symptoms seemed to dissipate as well. So, it seems to work for my body for now.
I truly believe that when we are playing with our natural hormonal make-up we may be throwing it out of balance, and when we are out of balance, there is now space for disease, and side effects. Break-Thur bleeding may just be one way your body communicates an imbalance within your special, individual make-up. I would suggest speaking with your doctor about this and seeing what other types of pills are available as well as other birth control options. Work as a team with your body and your doctor, and remember, this is the doctors "practice" and your body is what they are practicing on, so you get to be "patient".
If you're at all interested in taking an alternative approach to your health and finding out the root of why you're body is responding this way to the pill, give BodyTalk a try. It is a great way to bring balance back into the body and let your body heal itself. Here is the link for the lady I see, Lee-Ann Connelly. I have had amazing results in all areas of my life, due to my BodyTalk Sessions with her.
http://alternative.meetup.com/252/about/
Good luck with your journey to balance!
V. Dautel
http://www.elementsofserenity.com/home