I have that now too at 39+5. I've had it since about 20 weeks now and when I asked my dr she said its could be from extra blood flow down that direction causing it to swell up every once in a while and certain things will make it worse and if its too much to handle I can try just relaxing and keeping up on my kegals to keep everything "tighter" down there. It could be the same thing you're having? If you're super worried, call ur OB and ask about it. But if you think it could just be some swelling from irritation due to sex and walking then try taking some acetaminophen (Tylenol) and relaxing to see if it goes away.
I had that feeling but i always got told it was becuz everything is opening for when u go into labor or baby is just putting pressure down there but if u are really worried just call ur dr or goto the er u never loose nothing by getting checked
When I have sex with my boyfriend my vagina hurts so bad...not on the inside just the outside like you describw it. I'm also 16 weeks.