I took clomid for a few cycles this year before conceiving. One thing you want to be sure of (which is irrelavant if you are now pregnant, in which case, congrats!) is that you should be having sex not only on your "three days" but also in the day or two leading up to that time. Sperm last for 3 days, so that will help increase your odds. Also, it is REALLY helpful to do ovulation testing when you are taking clomid b/c it can be difficult to guage whether or not you actually ovulated if you don't take the tests. If you did not ovulate within that normal window, then the Dr. will give you some progesterone to get you to have another period so you can then take the clomid again. If you did ovulate, then you will either get your period shortly there after or you will be pregnant. I don't know of many situations in which you would miss a period after taking clomid unless you were either pregnant (hooray!) or did not ovulate, in which case you want to be able to tell your Dr. that so that s/he can up your dose for the next round.
Either way - niki_beth is right - if you are 2 days late, especially since you took the clomid, you should test positive if you're pregnant.
Good luck!
Sorry, I don't know anything about clomid... but what your describing could very well be pg symptoms! Unfortunately, pg symptoms and AF symptoms can sometimes mimic eachother very closely... If your 2 days late already I would go ahead and test!! If it is neg and you don't start in another 5-7 days test again (my first test was neg... but I got a pos 4 days later!!)
Good Luck to you!! And LOTS of baby dust!!!!!
I just started taking clomid too and they said that side effects can be the same as AF symptoms but you could for sure be pregnant! :) congratulations if you are! :)