That's new ...knee wobble when walking no pain?

Sued0nim

So 2 weeks of gym, lots of walking while on holiday (5-10 mile walks daily and swimming)

Gym with trainer on Tuesday...squats at 60kg, then 40kg to work on depth ...5 sets, plus lunge jumps with weights plus interval training on treadmill (1 min inclines at 15/10%) ..major backside and mainly thigh DOMS for 2 days, still tight ...walked about 5-6 miles each day

Today, day 3, legs still tight but knee has been occasional wobbling like my right leg is giving out when I've walked for a bit ...but happened 5-6 times when walking...no pain just annoying

Anyone know what this is, how to treat it and whether it really needs checking ..and can I go to gym