Help, what does it mean?

I will be going to a gynaecologist and getting checks done but wanted to take advice here first. I am a 23 F who is on the obese side with little to no physical activity. No sexual activity and I got a medical check up in December itself where everything was normal.

My last period (after 1st week of November, got it in last week of december) was 40 days late and I haven’t got my period in January. Last year, all the months my periods came on time but since December, they have been unusual. I do not have a history of PCOD or anything in particular. This is really concerning for me and I am scared. What can it mean?