E2 results with follistim Q

Hi everyone! I am currently attempting IUI. This is my first cycle. I am on CD 11. I have been taking 150 follistim. Had bloodwork done yesterday and my e2 or estrogen levels are only 146. From my research this seems low. RE has me continuing the follistim 150 tonight and tomorrow, then has me coming in for an u/s on Fri. So, long story short, will I be able to trigger Fri? I ovulate naturally but irregularly, is it possible to ovulate naturally before the trigger? This is my first month, so if it is unsuccessful is my protocol likely to be tweaked for better results next time? Thanks for reading! Anything is helpful!