Um, well, it's either a tick or it isn't. I've (very unfortunately) had to deal with a number of ticks on all sorts of animal species, and they're pretty easy to identify for me. If it's a swollen thing with little legs attached to your dog's skin then it's probably a tick. Either remove it yourself if you know how or get the vet to remove it and discuss tick identification with you.
I'm fine with just about every creepy crawly in the world except for ticks. If I find one on me or my dogs it'll come close to sending me into a nervous breakdown. A couple of weeks ago I took my dog to the vet for an apparent skin infection. It was mostly concentrated on one side of his body, but when showing it to the vet tech I felt a couple of bumps on his other side. I was in mid sentence saying "Oh, it feels like there's a little bit of it over here too..." when I looked at/felt one of the bumps and immediately freaked out at the vets saying "Holy heck, that's a TICK!!!" and scared the poor vet tech. It had evidently attatched itself that morning and the tech was kind enough to remove it for me