OvuLate before trigger??

Afternoon... I done my trigger shot at 10pm last night, I was at the hospital yesterday morning and had one good sized follicle and a slightly smaller one..they told me to trigger last night and then go back tomorrow for the iui... Well last night on the way home from work, I had a dull achey ovulation type pain... Could I have ovulated?? I know it's totally possible, but I was only cd11 yesterday, which is still a bit early for me..l done an ovulation stick yesterday at tea time and it was negative... Could it be negative and I've still ovulated?? Since taken the trigger, I've had no pain/ discomfort. Any advice would be fab thanx .... Am a bit of a worrier when it comes to all things fertility lol xx