Pregnancy?

I want to know if the chances of getting pregnant by someone who used a condom is lower than getting pregnant by someone who you have not been using a condom with for over 2 years is? What are the chances?

Secondly, I’ve been experiencing nausea, specifically car sickness out of no where, always tired, more hungry I’m not sure if it’s just PMS or if I may be showing early signs of pregnancy? My period is supposed to start today I am waiting to take a test until I’m a week late.