SOMEONE HELP ME

I need your guy's help. I'm getting really scared and freaked out. I usually have 30-35 five day cycles , I guess I'm irregular. I got a 49 day cycle in May. Then in June I DID NOT HAVE A PERIOD. So I miss that month. But then in July I received a period like usual just instead of five days it was 6 and the cycle was 34 days. But now this month I still have not received a period and its the end of the month. Looks like I'll miss this month to. Right now im at 53 days TMI at the moment I'm pretty dry, barely have any discharge in my panty. I did have sex but used protection and nothing went wrong with the condom. Couldl u help WHAT MAY THE CAUSE