Ultrasound yesterday, just curious what you guys think...

So I got my ultrasound to see we’re my follicles are at and they said I have an 18 and a 17.something, told me to take the trigger shot tomorrow which would cause me to ovulate 36 hours after. I just don’t want to ovulate early cause I’m doing timed intercourse. Plus the lady made me think she doesn’t know what she’s talking about because she thought I didn’t have my tubes which I do my left is just blocked. So I had to remind her of that also.. i just hope she’s right on when I should take my shot.