Groin Pain

I had a similar experience about 3 months ago.  Had a pretty intense, longer ride.  I woke up the next day with an excruciating soreness in my groin.  I rested 2 days and it felt great.  I went ahead and did another bike.  Woke up the next day with the same type of pain, except this time it took 2 weeks to go away.  I ended up missing about 5 weeks with that injury.

Unfortunately for me, I am now dealing with another groin injury on the other side... currently 5 1/2 weeks into the injury and doctors have no idea what is "actually" wrong.

Lots of things to consider in the area; would see PT who works with athletes or sports med doctor; any time it hurts it is for a reason whether it be a strain which will heal faster if given a little bit of rest but it may be a mechanical defect which is likely to recur and will utlimately progress turning a short lay off into an injury riddled season; the ' groin ' is pretty non-specific area - could be a hip flexor, quadriceps  or adductor depending on what the exact area is; it sounds like it is early enough to avoid more long term injury; also - were you fit on your bike by LBS or another person certified (some PT do this also depending on their background training)

good luck and good training

There are a TON of things that cause groin pain.  I wouldn't over do it if I were you.  I would try a little running and see what happens.  I have been fighting a groin injury since march.  I have went to SEVERAL Dr.s and none can find whats wrong.  The more I tried to do the worse it got.  At one point it was so bad I couldnt even walk a mile.   My symptoms also include pinching of the nerves causing pain in my legs and every once in a while testicle pain.   Its been a very frustrating injury to deal with.   The only possible diagnosis so far is a "sports hernia"   But that seems to be a very broad injury.      
I would take it easy and see if it gets better!   Good Luck!