NHS/private fertility UK

I’m 22 and wondering if anyone from the uk can help with telling me the first steps in trying to get help me and my SO have been trying for 4 years he’s now 27 and wants children I’ve never even had a scare or miscarriage and we’ve been having unprotected relations since we’ve met regularly we’ve tried safe lubes all the fertility tablets and tracking nothing I did have some tests done like blood and a internal check but they said I was fine and I left it because it was becoming to stressful at the height of corona virus now things have calmed down I need to know wether there’s a point to go the nhs route because it can take years or go private and also any recommendations for north London uk would help a lot thank you