Dear BethScholz: Usually we would expect a woman's "natural" pattern of periods to return within three months of stopping birth control pills (BCPs). It sounds like you did have some flows after coming off BCPs, but nothing since June. This suggest that any problem would be over the past two to three months--hope I am tracking you correctly.
If the pregnancy test is negative then the next most common cause of a missed period is not having ovulated that cycle. In a normal cycle, estrogen is produced all month. Estrogen is responsible for building up the lining of your uterus so you have something to shed each month.
In a normal cycle, progesterone production increases following ovulation. Progesterone "stabilizes" the uterine lining in preparation for a possible implantation of a new pregnancy. If you are not pregnant that month the levels of estrogen and progesterone fall, triggering the release of the uterine lining—your period. So, if you do not ovulate, the estrogen build up of the lining continues, but without the usual ovulation associated progesterone. Thus, the hormone levels don't decline, and the lining stays up inside the uterus—your missed period.
If you have been several months without a period, a gynecologist may give you some progesterone in a pill form (eg Provera 10 mg for 5 days). Within 48-72 hours after stopping the progesterone your "progesterone blood level" will fall, triggering the release of the lining that has been building up. Many women report that these periods are very heavy-- as though several months of lining are shed. Your GYN may have in mind for you to take some type of progesterone over several months to see if your cycle will re-regulate itself.
There can be MANY causes for not ovulating: low thyroid, pituitary problems, ovarian cysts, physical stressors (eg sudden increases in exercise, crash dieting), emotional stressors (problems with boyfriends/girlfriends, children, finances), increased body weight, anorexia, rotating shifts at work, etc. My best GUESS is that a blood test will be for low thyroid and a pituitary hormone ("prolactin").
In terms of having more mood swings, gosh it is hard to make a definitive answer. It MIGHT be contributing to more moodiness, but the studies are not conclusive. On an individual basis anything is possible.
Lastly, everything I have shared is based on an assumption that you are not in your late 40's. If you are in an older age range your GYN may be testing not only for missed ovulations, but also for the onset of menopause.
Yours,
Jane