Sounds like you need to go back to the doctor. If you have a distended abdomen, there could be some other causes, including ovarian cysts, ovarian cancer (exceptionally rare) or fibroids. It is extremely unlikely that you're pregnant, but there have been cases where women do not have the tell-tale hormone markers in their blood or urine
whatever is causing your belly to grow is probably pushing on the nerves that go to your vagina and is causing the tingling you've noticed.
Please make an appointment right away (and don't let your doctor put you off, you know how they can be).
Come back and let us know how it goes.
Take care.