Thank you for your question!
Thanks for asking a great question!
I'm a big fan of Fluoride rinses (ie. ACT). I have been using one every night for the past 30 years and recommend them to most of my patients for raising resistance to tooth decay and helping prevent or lessen tooth sensitivity. Once a day is fine, but remember to avoid rinsing with water after using the Fl rinse for maximum benefit. It will continue to "soak in" for the next 30 mins. If you want to rinse in the morning, I would recommend an anti-plaque rinse such as Listerine or Crest Pro Health to decrease plaque bacteria.
Hope that helps and keep up the great work!
First of all, I don't think there will be any problems with the baby, especially if the x-rays taken were digital which is typically about 80% less radiation than E-speed film x-rays. You said "routine" x-rays were taken. Assuming this involved only 4 BW's, that's even safer than say a full set of 18 or so images. I always compliment my pregnant moms for having their teeth checked and cleaned, so you can rest assured that having your cleaning and effectively reducing your overall level of inflammation will benefit the baby and make up for any negligent amount of radiation exposure. Also, if any dental pathology would have overlooked that can be much worse for the baby...such as an abscess for which you would often need to take Antibiotics etc.
If you are worried about what can be done from here on out, I would consult your OB-GYN, but I think there will not be any issues.
I hope that helps!