The general solutions for the harmonic oscillator differential equation fall into four general categories: 1) Undamped: [math]x(t) = Ae^{i\omega t}[/math] This is a free-running sinusoidal oscillation that doesn't change over time.
Key Facts. 1  Itâs normal to have mild cramps during your period. 2  Menstrual cramps often start 1-2 days after your period begins. 3  If your cramps donât get better with over-the-counter medicine, you should see your health care provider.
Persistent pain after a woman's period has ended is usually a sign that something is wrong. Ovarian cysts may cause menstrual cramps after a period. Irregular ovulation may cause cramping after a menstruation. Cramping menstrual-like pain could also be the result of a recent intrauterine device (IUD) insertion. Women with polycystic ovary syndrome (PCOS) may experience pain following menstruation. A reaction to birth control may cause cramps.