the 48 hrs following chemo is when your immunity will be at its weakest. I would avoid swimming in a public pool during this time frame as pools tend to have a lot of germs. Unfortunatly this is when you will be hyper from the steroids and you will want to go and do stuff. If after the first chemo your bloods seem to bounce back without any issues then I would go to the pool after 24 hrs after chemo.
Basically what I am saying is if you are not having any issues from the chemo then go and do your normal thing but if your bloods seem to not be bouncing back to normal levels then be learly of anything that might be a high risk environment.