yeah, plants begin rather small and due to that take some time for photosythesis and growing... 72 hours for germination is quite ok, but so far it sounds like you're doing fine.. i hope the lamp isn't too close, as the seedlings are still rather sensitive at this stage, so be careful with the light intensity and gradually bring it up (if your lamp has a dimmer, then either this way, or just ensure that it hangs rather high, and then gradually lower it)..
i also suggest creating a grow diary here, then we can see the progress, and how your plant is doing, and if there are further questions or issues, it's much easier to see what steps have been taken over time, and quickly chime in if needed..
happy growing!