Bro, that is exactly what happened to me several years ago. Definitely go to the doctor and have it checked out.
What I was doing was bent-over barbell rows. I felt a sudden sharp pain in the exact same area... between the thigh and lower ab area. Turned out to be a hernia. If you don't get a hernia repaired soon enough, it can become worse. The sooner you have it repaired, the better. And the thing was, that it only hurt for a few minutes, then the pain went completely away, and never came back. Nonetheless, it was a hernia.
If it turns out to be a hernia, don't worry about the operation. It's a breeze, and only takes about an hour. The recovery from it was a pain in the ass though. I mean, it was HELL just getting in or out of bed. It would literally take about a minute to get in bed. It took about a week for the pain from it to go away.
Now as far as getting back to training after the operation goes, it was about 2 weeks, then I was back in the gym... just training light though, doing small parts like bis, tris, delts, calves etc.
So, go get it checked out, and you should lay off the back and thigh work til you find out what it is... just in case.
Good luck bro.
KB