Why am I not getting my period?

So I haven’t had my period for like 3-4 months starting November. But in December, there was a 4 day period where I was spotting. I was really confused and didn’t understand why I was spotting but hadn’t gotten my period. This month, I still have yet to get mine and all when I think I have it, it’s just discharge (who can relate 😂). I’m not really sure if I should make a doctors appointment or if maybe it’s the irregularity since I’m 16? The only thing I can think of that it might be is the stress I’ve been having from work. Any thoughts?