should I have doubt ?

Bri • Married and mother to babygirl💓
So I've been trying to conceive for 8 months. So all of a sudden I'm a day late for my period so for the fun of it i think let me take a test . So I ended up taking 3 . All came out positive . I called the doctor and I go Monday to talk to them and to confirm . So since they said " confirm " should there be doubt I'm not pregnant ?i do feel nauseous and my stomach feels different , but I've also read that if you think In your mind that you're pregnant , you can trick yourself into having those symptoms. I don't know I might just be being paranoid because I've wanted this for so long I want to make sure it's real .