Dull pain in right thing near goin

[Pritchy]

Hi, I have been experiencing this pain for a few months now.  It's very sporadic - sometimes I will feel it once during the week, other times I will feel it 5 or 6 times in a day.  I have felt it occasionally in my left thigh, in my right calf and in my right armpit, but it's mostly in my right inner thigh near the abductor muscle in my groin.  I usually feel it when I'm sitting at my desk, or on the couch at home, but sometimes I have felt it when laying in bed or walking around.
The pain usually lasts about 10-15 seconds and then goes away.  The best way I can describe the pain is it feels like a dull ache, but on a pain scale of 1-10 (10 being excrutiating) the pain is about a 3, so it's more uncomfortable than anything.  But each time I feel it, the first thought that goes through my mind is of blood clots.
I am a 38 year old male, 5'10" and currently weight 220lbs, although I am trying to lose weight at the moment.  I excercise regularly (running, volleyball, gym, used to swim competitively) so I know what it's like to have sore muscles after a long run for example, or to pull a muscle, so I know it is not that.  I am asthmatic and it's under control, I don't smoke, never have, and I am a social drinker.  I am currently also taking Verapamil (80mg) for cluster headaches
Could this be something I need to worry about?  Any advice would be greatly appreciated.
Thanks in advance.