Yes, take it from me - I took tetracycline for 6 years! Little did I know what I was doing at the time. If you think like I did "oh well when I stop taking it, the good bacteria will flourish again" then watch it! It takes effort to put the good bacteria back. And the truth is, pro-biotics, while good and important don't all STAY with you - you have to take them for a long time and research the ones that WILL colonize your body, because a lot, most actually, get killed by the stomach before they even get to the intestinal tract.
Not trying to scare you - if you're on antibiotics for a specific purpose for a short time - well it's not like me being on them for 6 years straight. However, depending on the antibiotic and the person, sometimes all it takes is one or two rounds. So if you must take them for a bit, do eat yogurt and do take pro-biotics. One of the known probiotics to actually take hold and colonize your digestitve tract is Lactobacillus GG, but remember, there are over 300 beneficial bacteria down there.
Antibiotics have their purpose, but don't stay on them any longer than necessary. They will NOT help in the long run with parasites.