Good call on the 15 days. Just finished 200 EQ ewk with 500 test ewk. HCG should be used during your cycle to stop your boys from shrinking. If you use it after the cycle it actually supresses your natural test levels from recovering... not to mention it could give you some bitch tits.
I would wait 15 from the last shot on the clomid. Take 300 mg's day one. Then 100 mg's each day for 10 days. Then 50 mg's for another 10.
Best of luck.