It is pinched a little, but doesn't look like PM to me. I'm no expert though, keep an eye on it until you figure out why its a little clamped or it improves. The mantle looks good and puffy, extended. If it's PM its early stages.

You could always do a freshwater dip if you're concerned. But be careful to match temperature and pH. Fresh water dips are stressful for clams, but not fatal if done properly, even for 30 minutes or more.