だけど (used at the end of a sentence)

Question

I can't quite understand the meaning of dakedo here.

予定日は過ぎているから どっちかは分かるんだけどなぁ。
We are passing the scheduled date.

(This is what I can understand from this sentence about a baby born date.) I'm really confused about だけど.

Answer 1

This is really a case of けど at the end of a sentence. There are several questions about this already:

• けど at the end of the sentence?
• けど in the end of sentence

Your sentence ends in 分かるんだ, where ん = の is nominalizing the verb 分かる and だ is then needed to make it a complete sentence (and けど is following that). The sentence also could have ended in …分かるけどなぁ. For this you can look at

• What is the meaning of ～んです?

Back to your example sentence, 予定日 is a keyword here and refers to the estimated day of confinement ("due date"). どっちか means "which [of two options]" and in this context the two options are "boy or girl".

予定日は過ぎているから どっちかは分かるんだけどなぁ。
We have passed the due date already. Well, we already know which it's going to be...

Answer 2

It's hard to understand for me but the full statement could be the following.

"予定日を過ぎているから、もう赤ちゃんは生まれているのだろう。だとしたら、男の子なのか女の子なのか、見に行けばどっちか分かるんだけどなあ（仕事で行けないけど）"