Need help - injury

So, I picked up some Deep Relief and I have to say, it actually works—the pain relief is legit. But here’s the weird part: whenever I run my hand down my left leg, I can feel this tiny, tiny little bump.
The actual aching has subsided, but the lump is definitely still there. My doctor basically told me I just overdid it at the gym and strained my muscles, but I don't know... I'm curious to hear what you guys think!

So, how exactly did you end up wrecking yourself?