Hello. Feel free to ignore my advice as all children different.....
My DS is 3.4 and trained about six months ago. He is completely dry at night and has only had about three accidents (all at nursery, none at home) since training.
BUT....it took three weeks from first attempts with potty to using a potty with no issues. He did not get it in a couple of days. I don't actually know any of his friends (boy or girl) who only took a couple of days, although I have read that some do. And then it took a couple of months of carting round the potty everywhere before he felt confident enough to use the toilet.
I'd describe the process like this:
Week one:
Cold turkey, no nappies at day time
DS shows no sign of "getting it"
We offer the potty every 30 mins or so
DS endlessly wees in pants and poos only in the morning in his nappy
No bribes seem to work
(I feel depressed about potty training)
Week two:
DS very occasionally gets his wees in the potty
DS never asks to use the potty
We eventually find a bribe that works after much experimentation (incredibly sour sugary sweets 
that he would never be allowed normally)
DS starts to show mild interest in using potty if he gets a sweet and masses of praise
(I feel depressed about potty training but can see slight progress)
Week three:
DS now very enthusiastic about getting a sweet for performing and praise
Does wees and poos on potty
Starts by end of week to ask for potty so he can have a sweet
Is now dry most of the time
After that, we carried on the sweets for a couple of weeks with enormous praise. We carried round the potty for a couple of months as he was scared of the big toilet. Then he got over that and was happy to use the toilet every time. He asked to take off his nappy at night after a couple of months and has stayed dry.
At the time, it seemed never-ending but I now see that a few weeks cracked it totally. I gave myself two weeks and said I would give up if there was no progress. There was, so it was worth perservering. I'd give it two weeks personally if you can do it. You are changing a lifetime's habit for him so it can take a bit of time.