Challenge No. 1: PMS
The lowdown: Premenstrual syndrome is the range of symptoms that occur 5 to 11 days before your period, thanks to plummeting levels of estrogen and progesterone. Warning: PMS can worsen in your 40ssince hormone levels tend to fluctuate even more widely during perimenopauseand whenever you're stressed out.
What it feels like: What doesn't it feel like? Hello, breakouts, sore breasts, bloating, diarrhea, headaches, backaches and mood swings.
Rx: Lifestyle changes can help a lot. Limiting salt intake minimizes fluid retention and bloating; getting enough sleep and exercise will boost your odds of feeling good during this phase. If you get PMS like clockwork, you could start taking a low-dose birth-control pill to stabilize your estrogen and progesterone levels. If none of the above works and your mood swings are severe, it's possible that you might have premenstrual dysphoric disorder (PMDD). Talk to your doctor: Taking an antidepressant such as Zoloft or Prozac can help.
Challenge No. 2: Pregnancy
The lowdown: That plus sign on your pregnancy test means there is human chorionic gonadotropin (hCG), a hormone made by the placenta after conception, in your systemsending estrogen and progesterone levels surging. They drop dramatically after childbirth and stay low if you're breast-feeding.
What it feels like: Blame hCG for morning sickness in the first trimester. Rising estrogen and progesterone levels make your breasts larger. They also dilate your blood vessels, leading to relaxed joints and muscles, which can cause back pain. The drop in hormones after giving birth can result in moodiness for a few weeks.
Rx: Ease nausea by eating small, frequent meals. Your doctor might recommend vitamin B6 or prescription meds if your vomiting is really bad. After pregnancy, if you have baby blues that just won't go away, you might have postpartum depression. Don't be afraid to talk to your doctor, who can prescribe antidepressants (some are safe to take while nursing) or even low levels of estrogen. Therapy can help, too.