HSG really the next step?

I'm 36 and TTC for 5 months. My obgyn wants me to do an HSG now (along with hubby doing a semen analysis). I'm waiting for my period to start (which is late btw) so I can schedule the HSG. But I'm hesitant to do the HSG. My bloodwork was normal, I've never had STDs / pelvic infections, and I don't have any history of cysts / fibroids. Is an HSG necessary?