Hi

My dog is about 7 weeks pregnant and her nipples have grown.
Odd thing is that only her 2nd pair have increased in size but the other 4 haven't.

Is this normal?

I believe it's a small litter close to her chest because her ribs have widened and her waist, from above, is no longer there. Like her chest and mid abdomen are the ones that thickened, not her lower abs. Her tuck-up is still seen from the side.

Thanks