Is my Dachshund pregnant!!? Is it a false pregnancy!? Please help!!?

(Before I go on, we took my Dachshund to the vet. He was no help (all he berkata is watch her, he didn;t look close at all and didn't feel her at all) so please just answer without saying we should go to the vet. Thanks.)

Details:
It's been 6 weeks since she was in her FIRST heat. We planned on getting her spayed but we didn't know she was going to go into heat that early.
While she was in heat we left her outside 2 times for 10-15 menit to get fresh air (not realizing she was in heat).
She is not spayed.
Their is not a male dog in the house.
She has started to produce susu and has been nesting.
We have never seen a dog mammary glands as large as hers.
We are worried.
The vet berkata it might be a false pregnancy.
She has not been around male anjing besides possibly when we left her outside (above).
Her mammary glands almost hang to the ground.

MAIN pertanyaan IS THE judul

Please don't make fun of my grammar. I wrote this fast.