Should I check if I have OCD

To keep it short; I’ve been dealing with unwanted thoughts/imagery in my head, I check the windows/taps/wash my hands excessively and do that infamous counting system, and I have compulsions/have a certain way of doing things for checking all the plugs/devices at nighttime… These have all been with me since I was about 14? (I’m in sixth form now)
My concern is that these fluctuate in intensity and it gets a lot worse at night time. While in school I get only small intensity compulsions
I’ve done a bit research on OCD and things like that and it’s helped me, but I really want to get clarity on my situation. My parents may neglect this unfortunately but I think I need some support on my situation. I’m unsure of what to do really

Yes, I think you should get an assessment.
What are these unwanted thoughts/imagery in your head? Based on this or something else?

I figured. But I found people with similar circumstances as me, so it made me feel less alone in my situation
I would, but I doubt my parents would let me currently, so I’m finding ways to lessen my symptoms

As you are a sixth-former, and thus over 16, there is no question about the doctor keeping any consultation or information shared therein confidential. There is no need for your parents to even know you've seen the doctor, never mind what you discussed with him - the patient-doctor confidentiality is complete.
In the end, it is you suffering from these symptoms, not your parents, so I would urge you to see the doctor confidentially and discuss what you are feeling with him or her. Your health matters.

OP just make sure if you arrange an appointment that you use a different phone number than your parents and ask them NOT to use your parents number (usually a family is woth a GP and the parent's number is the contact number for all of them), or at least think of another excuse for the doctor to be calling you just in case they do call your parents
This happened to me

So the GP called your parents instead? I’m kinda struggling with ocd symptoms but not sure if I really have ocd. I don’t want to talk to my parents about this but this has really impacted my life. I wanna get help but don’t know how.