Over 45 and having symptoms of pregnancy

Hi,

I am 46 years old, I have a 24 yr son & 19 yr daughter.

For the past 2/3 years I have not been having regular periods (it can disappear for over 4-6 months, then reappear for 2 months) .

For the past 2-3 weeks, I've been experiencing severe pregnancy symptoms and I'm actually scared of going to the Doctor to check if I am pregnant or not.

I would like to have a baby at this point in time and whenever I g to the Dr, urine results come back negative.

The symptoms I am having are: nausea, headaches, breasts tender, growing and whenever I've had something to eat, they fill up. My stomach is getting big, some smells and food make me feel billous.

What could these symptoms be other than pregnancy?

Please help and advise and I will go see my Doctor.

Thanks