I have done that before too, skipped a period. And my next one was always heavier due to not having one for 2-3 months. Your lining was probably just thicker than normal and needs more time to slough it off. I doubt you are pregnant. My doctor told me doing that was just fine. You probably have an excess of hormones because of skipping a period and that's why you feel different. If it doesn't go away soon though it's a good idea to go to the doc.
Just so you know though they do make birth control that makes it so you only have a period every three months, Seasonique. Maybe you could talk to your doctor about that. They also have LoSeasonique which I am on, it has lower dosage of hormones and you still only get the period every three months. I have only been on it for about 3 and half weeks so my body is still adjusting. So far I have been really crampy, sore boobs, and PMS but I am always like that when I switch, it's normal for me.
if birth control was ment to be taken and have a woman miss their pills......they wouldnt put sugar pills in the pack!
you could very well be prengnat since it doesn tseem like your using condoms and your playing with your birth control pills.
if you think your pregnant than take a test. what your feeling can also be because your playing with your pills (hormones)