Try out these three stretches once or twice per day for at least one week. Note, do not do these if any pain during or after.
Kneeling hip flexor stretch: 2 sets, hold for 30 secs each side. *squeeze your glute on the keeling side to stretch it better. *kneel on a pad to not hurt your knee caps. *keep feet within hips width and keep hips pointing forward.
Seated Figure Four: 2 sets, hold for 30 secs each side. *keep hips level and avoid hunching over. *should not feel this in the knee, keeping your foot flexed (unlike the lady in this photo) will help support the knee in this movement. Feel like you are sinking into your hip rather than crunching down.
Seated chair groin stretch: 2 sets, hold for 30 secs. *slowly bend over while squeezing glutes to pull the inner thighs away from each other. *for a different stretch, the palms of your hands can rest on the muscles slightly inside of the knees and gently push outwards. Wider feet=more stretch