Master Cylinder Leaking Possibly?

Vehicle 2017 Tacoma LB TRD Off Road 4x4. Last weekend I went to get in the truck and on the floor mat I noticed a little dark line (fluid) and a small wet spot. Looking closer it appeared to have came from the back of the master cylinder. I wiped off the floor mat and a little residual on a metal part. I inspected the engine bay and there was plenty of fluid in the reservoir and no leaks in the engine bay. I drove the vehicle probably 40 miles or so with plenty of stop and go and inspected for more leaks but did not notice anything. I have only owned the vehicle for a few months so still getting used to it too. Question/ assumption is that once this part starts to leak it’s only a matter of time to have the leak get worse right? Question though is if it leaked a little bit once does it make sense for it to not leak again?

I have a 3,000 mile trip scheduled in 4 days and plan to use it a lot so this puts quite a bit of concern to take the truck or not. If anyone has some insight on this issue please share.