Need help diagnosing a tire problem

I changed my first flat a few days ago. All went well, but now there seems to be a bulge (or something) in the tire. I feel a slight bump when I ride, and if I watch the tire in relation to a fixed part of the bike, there's obviously a slight variation (I guess a slight bulge). When I run my hand over the tire, I can't find anything, and the rim looks okay.

Any ideas on what the problem might be would be appreciated. I plan to take the tire off and look at it, though I haven't done that yet.

TIA,
Pam

Is the bead set properly in the rim all the way around? Can you see a variation in the sidewall to show you the bead is deeper in the rim in one place than it is in the rest of the tire?

Try letting a lot of air out of the tube, push it around a little to break the bead, but leave the tire on the rim, then re-inflate. That would be the first thing I'd try.

Yes, probably not seated correctly. If there's a spot that bulges out, it could blow off the rim if you don't get it seated correctly. Don't keep riding like this. Let out the air, pump it up to about 20 psi, and check the bead all around, pushing or pulling the tire with your hands until it is even. When it is all even, then pump it up to pressure. It's easy for the spot right at the valve to end up high. After you install the tire, before you add any air at all, push the valve up into the tire, make sure the tire bead is down into the rim, then pull the valve back into it's proper place.

Is the bulge near the valve or 180º from the valve? Sometimes the tubes, if too small, when inflated can "bulge."

Try inflating the tube outside of the tire to see if it does it. If not try checking the bead of your tire and that its connecting well.

What brand is it? I had a set of specialized Robaix blow on me and was a manu defect. Check your tire brand online for any recalls