I am 16 years old and i have had very irregular cycles since i started my period, i know this is common when youre younger but it is getting more irregular. my last period was 4 months ago which is the longest i have gone. am i possibly infertile?

Hard to say: Some women who are eventually shown to be fertile (know one with three kids) are quite irregular and or only have 3-4 cycles/yr. You can meet with an OBGYN to discuss this. Sometimes the BC pill can be used to make your menses predictable & regular & once off you may achieve a more "normal" pattern. Either way the irregularity does not mean you are infertile.