From my experience it didn't really hurt that much. About the only time I was in any real pain was a few hours after the surgery when I was sitting in the hospital bed, and even then it was only like a throbbing pressure, nothing big. Afterwards for the next few weeks there was a mild discomfort, but usually when I moved around. You'll probably be more concerned with your mobility than pain.
As for swelling, not everyone swells up. The only swelling I got was when they took off the pads and that was for a few days afterrwards. (BTW, make sure the nurse doesn't wrap the tensor too tight after you get the pads taken off. When I went home after my post-op check up I nearly fainted in the shower after taking off the tensor wrap- this is because of the sudden relief of pressure).
Now the pads are noticeable, but only if you wear one layer. Even with one layer it just seems like you've got a weird rectangular shape strapped to your chest (the top part being the most noticeable by making a crease). Just wear a few layers and you'll be fine. The tensors don't even make much of a crease. Even when it's visible (which it would only be from wearing a tight shirt) it just seems like you got a wife beater bunched up underneath.
As for recovery time the doc said I you only really need like four days before you can be mobile (depending on how much labour your job requires of course- mine is minimum) . I didn't even really need that. In fact, the day I got back from the hospital, I did the dishes and tossed out the trash. Pace yourself though, recovery can't be rushed.
Now as for telling other people: I personally didn't do it, and it was a hard ruse to uphold, but I managed. Though it will make it an easier ordeal, there is the long term ramifications that you have to factor in too. It's kind of embarassing to tell your parents, but then again, these are the people that changed your diapers so they might understand. My suggestion is that if you are going to hide it, make sure you plan things before hand and come up with consistent cover stories. You have to get to St. Joe's hospital a certain ammount of time before the surgery (I believe 2 1/2 hours), but if your surgery's at like 8:00am that means you'd have to get there at 6, but the subway doesn't even open until like 5:30, so try to get a later surgery time otherwise you might end up having to take a taxi at like 4:00 in the morning like I did. I'm not sure what the hospital policy is, but I came up with the excuse that my mother threw her back out and couldn't pick me up just in case they would try to call her or have a nurse escort me home afterwards. That way I got to stay the night in peace and comfort. By the way, even if you aren't in pain at the time, it doesn't hurt to ask the nurse for some tylenol 3s. Just save them for later and spare yourself the cost of a perscription.
This is just advice of course based on my particular experience , take it with a grain of salt. Good luck.