A: Having your tubes tied (or getting a bilateral tubal ligation) is one of the most effective methods of female sterilization. It is 99.9% effective. It is not 100% effective. In fact, nothing is....except abstinence. So, although getting pregnant after having your tubes tied is highly unlikely, it is possible. If you feel like you may be pregnant, the easiest thing to do is to take an over-the-counter home pregnancy test. The more likely explanation is that your periods are changing, as many of ours do after childbirth and as we age (although you are still very young!). It may also be that something else is going on with your health, which could be affecting your body and your menstrual cycle. Thyroid disease, for example, can cause fatigue, mood changes, weight loss or weight gain, and changes in a woman's menstrual cycle. If you aren't pregnant and your symptoms continue, I recommend having a consultation with your OBGYN.