I'm glad you're still going ahead with it as it's a wonderful experience. I'm missing it terribly as my hubby wouldn't let me swim with her once we found out I was pregnant with #2! Silly boy, we have a lot more happen to us during pregnancy that would be more worrying than being kicked by a swimming toddler!
Camryn is booked in to have gromits on Oct 8. She's getting them in both ears and they generally last 3mths-3yrs! Our key indicators were she stopped walking & started crawling, her speech is delayed and she cried & tugged at her ears constantly. As long as you are vigilant about it, it should be okay.
Ear drops and plugs were useless as she was actually sniffing the water up through her nose & it was not able to drain out sufficiently, therefore she got the glue ear. After she has the gromits it'll be a must that whenever she goes near water, even for a bath our shower, she'll have to use ear plugs as she isn't allowed to get water in her ears or all our efforts could be in vane.
Enjoy your lessons,
Peta, NSW, mum of 2 gorgeous girls