Hi.. It is difficult to predict the reason for the unexpected cause for the missing the period and then getting one and those symptoms.. My best guess would by you were pregnant and you may have had a miscarriage. It could also mean that you might have had a delay in the periods which can some time occur following infection and stress... The only means of confirming this is by consulting a doctor. And regarding getting pregnant, the best chances are when you are ovulating. This happens during mid-cycle, and not before or after the periods. You can calculate the day ovulation happens, if your period are regular.  Alternatively an ovulation kit  can be used to determine the day of ovulation... Good luck...

where can you purchase a ovaluation kit.when you get it will it tell you the day of ovaluation?

There are certain tests for this. Speak to your gynec. It includes measurement of body temperature, discharge and confirmed by ultrasound.