How many months pregnant are you?
今妊娠何ヶ月ですか？
How many months?
今（妊娠）何ヶ月？
「妊娠何ヶ月ですか」は「How many months?」という表現がよく使われます。より丁寧に質問をする場合は「妊娠」という意味の「pregnant」も加えると良いでしょう。
友人や仲のいい人には「How many months?」「何ヶ月？」と気軽に言いましょう！
Well, really it is a very personal question and unless the person you are asking is a very close friend, it is probably poor style or even rude to refer to 'pregnancy' in casual conversation. It is probably more acceptable to enquire when the baby is due.
「妊娠何カ月ですか」は英語で：
How many months along are you?
これは一番言う表現です。「妊娠」の言葉が入っていませんが、これを言ったら、妊娠中の話し相手がわかります。
When is the baby due?
この表現は実際に「赤ちゃんはいつ生まれますか？」に相当しますので、「妊娠何カ月ですか」に全く同じ英訳ではないが、関連する表現です。
＊注意点：こういう質問を聞く前に、話し相手が本当に妊娠中かどうかを確かめてください。妊娠ではない場合、怒られちゃいます。
Good luck! :)
When talking about asking a mother-to-be how many months is she, you can use "due/due date" as in when is she going to deliver the baby.
Also by asking "How far along are you?" you are asking how many months into her pregnancy she is.
妊婦さんに何か月なのか尋ねる時は "due/due date"（出産予定日）が使えます。
また、"How far along are you?"（妊娠何か月ですか？）と聞くこともできます。
The two sentences provided above are excellent ways to ask someone how long they have been pregnant for. The first sentence is very common when asking a woman how many months she has been pregnant for, but your listener will understand both of these sentences. I hope these two sentences and this explanation help you out!
アメリカ合衆国 
イギリス 
