Advice appreciated

Hi ladies.

I am 20 years old with a 1 year old, I really want another baby. My partner of 6 years has said we aren't trying but if it happens it happens. Now, I don't know whether this is early pms symptoms but I've been really emotional, happy one minute then upset the next, I feel 'heavy' in my lower abdomen and feel nauseous. I am due on in 5 days, could it be pregnancy or early pms symptoms? Never had any symptoms with my son so I'm clueless to what it is. My nipples are also sensitive. Any advice would be appreciated, thank you x