How long does hcg works once injected for ovulation to occur?

i was intructed to take HCG @630pm yesterday..gave me headache ,,been 12 hours already still didnt ovulate i just came from another bloodwork and ultrasound the lady told me one of my follicle did not rupture or release as yet so how long does hcg work..of 1cc to be injected near belly on.im loosing hope again...took serophene 2weks ago..mightve work a bit..then now HCG so frustrated..and impatient about this..when does it come oout..been ually active for 5 days straight..!!! and have been feeling gradually cramps for 2 days my follicle size is around 2.67cm ...doesnt it suppose to rupture already?help pls...advise..me thanks..