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.
Dr. Colin Kerr Dr. Kerr. 1  Uterine cramps: Pregnancy cramps and menstrual cramps typically feel very similar because the discomfort is coming from contraction of the same uterine muscle. Menstrual cramps, however, may be more severe since the muscles can contract more when the uterus is empty.