Irregular periods & pregnancy

I'm 24 and I work in Healthcare so I'm not "silly" but I am anxious. I have recently gotten into my first relationship and hoping to get intimate soon, but I am so scared of getting pregnant by accident.

When I was 20 I went on the pill for irregular periods but stopped it when I was 22 as during covid they stopped checking on me and before I knew it my blood pressure was 170/110 (High) and I felt extremely unwell mentally. Since coming off the pill my periods actually went back to almost a normal pattern and have been more predictable, but on occasion I will skip one or two and then have 2 within the same month.

My plan is of course to use condoms, but I am so anxious about what if I then skip a period naturally, is it really going to be a case where I'm potentially buying pregnancy tests every month?

I think I'm just looking for some reassurance in that I'm not just going to fall pregnant straight away and if I do thats just poor luck... I do want kids in the future but I've only been dating this guy a month 😅

Are condoms really effective? They are my only option as it was agreed I shouldn't have any hormone contraceptives and I don't like the idea of having anything stuck inside me that then has to be removed/replaced surgically.

I'm an over thinker as well so please helpful comments only, I'm just looking for some reassurance.