R.J.
Yup... any time you play with your hormones up to about 6 months of wackiness is to be expected. Most of the time things even out in 3-4 months or less, but up to 6mo is fairly common. Others, don't even blip, and are right back on schedule.
ALSO stress can delay a period indefinitely (as can dieting). In either scenario months to years of no period are common. ((It's one reason why so many women get their period the day AFTER they take a test -or to ovulate the day after. They were to stressed for their body to be in a normal cycle)). Anorexics lose their periods all together. The body's primary response is survival and menstrating/the reproductive response takes a backseat to what the body views as life threatening events. (Swing in adrenaline OR "starving" aka dieting = massive caloric reduction will do it every time).