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.
cramps usually occur 2 to 3 days before your actual period starts. Some women don't even experience cramping at all while others have it really bad (the good thing about having bad cramps mean that you will have an easier child birth when delivering your children). It usually stops two days into your period so it should go away if you do have your period coming up.