Swelling came back

[Truval101]

I got all four of my wisdom teeth removed exaclty 2 weeks ago. Everything went as expected. I originally got swelling the day after and it lasted for 4 days post op. Then it went away. I finished my round of Antibiotics last Monday. Last thursday I noticed that the swelling came back, but it was minimal, but still there. I had booked an appointment with my surgeon and he took a look and said it looked fine and that it was healing up and that there was just a bit of food stuck in the sockets and he cleaned it out . I still have swelling today, how is this possible if it's not infected? If it matters, I do smoke cigarettes, but i don't see how that could cause swelling. I did not smoked for 3 days following my surgery.