Is it normal to experience gas/bloating right after finishing a course of antibiotics? would probiotics help?

Yes and possibly: It is very common to have altered GI habits / symptoms after antibiotics. Probiotics do help in a good portion of patients.

Yes/yes: Taking antibiotics can have a profound effect in altering the normal biota of your intestinal tract. This effect can persist for months. Probiotics may help. They have been shown to help prevent antibiotic induced diarrhea. I use vsl#3. The capsules each have the amount of bacteria found in 10 cups of yogert. The sachets each have the bacteria in 45 cups of yogert.