Conversations I Haven't Had in Korean: "How Far Along Are You?"

The other day, my yoga instructor told me she was pregnant. Well, not in those exact words. "Me -- baby," was what she said. I said "Congratulations" in English (I don't know it in Korean) and then "Choayo" (that's good).

Normally at this point the polite thing would be for me to ask how far along she was. She definitely wasn't showing. But how do I do that? "Onje yo?" Literally, when, could mean when it would be due or when it was conceived, and I probably cound guess from context (in the future or the past) what she meant, but it'd be better if I could ask "When + [due date or conception date]?"

Sadly I don't know any even polite terms for intercourse, much less conception, and that wouldn't be the most polite approach, anyway. I could ask when she was due maybe by saying "Onje ai sargesseoyo?" (Literally, when will it intend to live, because I don't know a proper future tense yet.) Maybe "Onje ai sarolkeoeyo?" (When will it probably live?) But neither of those are terribly polite.

Being fluent in the universal lecture of gestures, my next thought was to try to communicate by hand movement either (1) a baby being born or (2) a baby being conceived. The latter is easy, but again, impolite, and the former ... well the best I could do was either (a) make a circle with my hands and gesture, using a forearm, something large coming out, or (b) make a basketball hoop with with my hands/arms and poke my head through.

Then I thought, "Perhaps I could even combine the gestures and completely humiliate myself."

This left me with only the typical stranded foreigner option: Wait for someone else to relay the information to you, if you're lucky. This approach beats offending everyone in eyeshot and earshot, though.

(Of course, by the time I had figured all this out four other people had entered the room and we had already begun yoga class.)