You can also use "おかしい" or "違和感がある(or違和感を覚える)" when you feel that something is unusual or something is difficult to understand. "変" and "おかしい" indicate that you feel suspicious of something depending on the context. "違和感がある" indicates that something is just different from anything that's usual/normal.
Meg and Amy are jogging together.
- Meg : We've been running for more than 30 minutes. Why don't we take a break?
30分以上走っているね。休もうか？ - Amy : Good. Can we sit on that bench over there? There's something wrong with my leg.
いいね。あそこのベンチに座らない？なんか足が変な感じがする(or足の調子がおかしいor足に違和感がある)。 - Meg : Sure. Are you okay?
うん。大丈夫? - Amy : It's not a big deal, don't worry about it. By the way, I like your shoes.
大したことないと思う、心配しないで。それより、良い靴を履いているね。 - Meg : Thank you. I like them too, but I feel kind of uncomfortable wearing them because they're so new.
ありがとう。気に入っているんだけど、新しい靴だから、なんかまだ違和感がある(or変な感じがするorおかしい感じがする)。
Meg and Amy are gossiping.
- Meg : Did you know that Sara is going out with Ken? I saw them together at the movies.
サラがケンと付き合っているって知っている？映画館で二人が一緒にいるのを見た。 - Amy : No way. You know she's dating Jim.
まさか。ジムと付き合っているんだから。 - Meg : Yeah, I know that, but they looked like they were having a lot of fun. Too much fun, if you ask me.
うん、そうだけど、すごく仲良さそうだったの。なんかおかしいと思う(or変だと思う)。 - Amy : Huh, that's suspicious.
ふんっ、変だね(orおかしいね)。
Ken and Leo are talking about the documents that they made for a presentation.
- Ken : We have to finish preparing for the conference. Have you already gone through the documents?
会議の準備を終わらせないと。もう資料チェック(or確認)した？ - Leo : Yeah, I've read all of them. And I just feel like something isn't right about it but I can't put my finger on it.
うん、全部読んだよ。何となく違和感があるんだけど、何でだろう!? - Ken : Okay, can you try telling me what we should change. We really don't have a lot of time for the preparation.
そうか。何を変更すべきか教えてよ。あんまり時間がないからね。