Fertility Specialist

I have had 2 early losses this summer and would like to go to a fertility specialist to get more comprehensive testing done. My OB seems very lax about everything stating “we will figure it out. You are getting pregnant so we just need to find the right formula for you”.. I think she means adding baby aspirin, maybe progesterone supplements, or whatever else.. idk. I feel like I have no clear plan for next steps even when I ask for clear answers. I’d like to pursue seeing a fertility specialist on my own .. Do I need a referral from my OB or can I just go in myself? For anyone that has gone to a fertility specialist, was it helpful?