Endometrium growth. Go for hysteroscopy?

Hello, Last month i was not on ovulation induction due to retaintion follicle. I was put on estrogen 2mg twice a day to check my lining for 15 days. I took tablets for 12 days ( coz i was not punctual, i used to forget) my et after 14 days showed 5.2mm. This month i had ivf stimulation. GF 300 & 75 hmg for 6 days GF 300, hmg 75 & cetro (Gnrh) for 6 days Along with medicines like probiotics, folinine, ecosprine etc I had 12 follicles in beginning, Later only 6-7 are expected in retrieval (is what doc said) This time my lining was 7.8mm Doctor says i need to perform hysteroscopy, as in stimulation lining should have gone above 8mm 4 months ago, when i had iui, my lining did went upto 10mm Should i go for hysteroscopy??