Help please? asap... im kind of confused?

Okay, it started last month, i missed a period and then this month I got a ten day period, i was very confused, i don't know what happened there, but its nerve wracking. I should be getting my next period soon. I had pneumonia for two weeks, two weeks ago*the pills made me feel sick so i stayed home.. ( i think i still have it but its almost gone if i do still have it) .. I've been feeling sick randomly lately after i finished the pills... do you know what could be going on?