Paranoid or is this something to worry about?

I'm 18 years old and a fortnight a go I had to use the toilet a lot more than I normally do, this has more or less stopped now. Unfortunately, every other morning I have nausea, some days I have a loss of appetite and my period is late by 3 days. I know 3 days isn't something to worry about, but my periods have always been regular though they have sometimes started a day early.

I am not sexually active at this time, and the last time it could even remotely be considered that I was, was 3 weeks ago and I didn't have sex or anything close to it.

I'm very probably just being overly paranoid, but when someone asked if I was alright because of having to use the bathroom a little more than usual I looked it up (thinking it was just a urinary infection) and I panicked when I read that it was also a pregnancy symptom. The same applies to the other symptoms.

I'm terrified of talking to my mum - even if it is just me being paranoid - I haven't taken a test and I'm a little wary of seeing a doctor in case it is just an infection and having panicked and gotten stressed out for nothing.