on trigger shots/ did I just ovulate on my own??

Hello all! My periods have started to be irregular from last year. AF visiting as late as 2~3 weeks. I am turning 29 this April and we are trying to get pregnant that month since we plan for a 2019 baby. So given the irregularity of my periods I have started tracking my fertile window since January with OTKs and with OB/GYN visits. I went last week (Friday) which was my cycle day 12 but there were no follicles. Went back yesterday (Wednesday) and the doctor told me there is a full grown follicle and that he would give me an hGC injection to make sure I ovulate. he thinks that even though the follicle is grown my LH hormons level are not enough to make ovulation occur. I reminded him that we are not TTC this cycle but rather 2 cycles later. I took a OTK this morning and after almost a week of negatives it tells me that I am ovulating. Well, my question is: do I really need an hCG injection even if my OTK has detected I am ovulating (or in my fertile window)? My main concern is the trigger shot giving me twins or triplets! TIA