Lots of things change in early pregnancy - and lots don't even though they should.
Here's how to confirm pregnancy. Watch the sun rise and set at least 21 times, and then do an ultrasound. While you are watching the sun rise and set, thing of beautiful things. If it's cloudy or raining, think of the miracles of these things happening to sustain life all over the earth. Breathe deeply, smell the outdoors, enjoy life!
And for God's sake, try not to obsess about whether your bitch is pregnant or not! You'll just drive yourself nuts.