Is this and ocd or do i have something else?

Every so often maybe not everyday i get a strange thought in my head etc. do this otherwise something bad will happen.. so in my head i am like blink 5 times or something bad will happen or hold onto the door for 8 seconds.. it is very strange sometimes i ignore it but i do sometimes trust that something bad is going to happen and because of that thought i literally cannot beat it as i would blame myself if something bad happened and it would be my fault. No one in my family would even think i have this problem but i think i need to overcome it i am 16 years old. I am not a weirdow i am a very normal average kid.. I have smoked quite a lot of cannabis over the past year and have just started experimenting with mdma.. could this be the problem i am wondering or cause the problem to become even worse! Please help just some ideas which may help me overcome this i dont want to go to a specialist or anything like that