You'll have to keep your fingers on your cup (and thus, in your vagina) as you begin to push it in. Point the top of your cup at the back of you, not up towards the top of your vagina — visualize pushing it towards your tailbone. At a certain point, you'll find that cup feels like it is securely inside you — not too much of the tip is hanging out of your vagina now. Now is the time to stop pinching the cup, and let it "pop" open.
Once it has popped, keep pushing it up into your vagina by the bottom of the bulb. I usually push a little bit against the edge of the stem with my fingertip, so that the tip of the stem is about even with the opening of my vagina. If it feels comfortable, and not like the tip of the stem is poking your lady meats every time you move, it's in there right.
原文 https://www.bustle.com/articles/76798-using-a-menstrual-cup-for-the-first-time-heres-our-step-by-step-guide 有詳細講。仲建議放完踎一踎低等佢走啱位。我自己通常放完郁幾郁pelvic floor muscles(即產後運動嗰隻停尿動作),有助隻杯啱位。