I'm late to reply to this, but wanted to respond because I worked as a medical scribe last year in the St Luke OB GYN office. I watched Dr. Revoir do lots of endometrial biopsies - it is a standard thing for post-menopausal bleeding (because you can imagine if you start bleeding after menopause ideally you look for the reason). Endometrial biopsies are not incredibly invasive. I mean they are (hello pelvic exam), but I think of biopsy and my brain goes cut off some cells with a scalpel or insert a needle - this is not that.
The provider places a speculum. Next imagine a syringe attached to a tube instead of a needle. The syringe has nothing in it when they start. The provider inserts the tube through the cervix and then opens the syringe which makes a vacuum and the tube sucks up the cells. The hardest part is whether your cervix is totally closed or not. If you've had a baby before it goes much smoother because your cervix is likely not exactly the same as it was pre-baby. (that's probably not a surprise to anyone). I think the tool is called an endometrial sampler. There's a decent diagram at the bottom of this page of what is going on.
Obviously some people are better than others at being gentle and you'd want to pick a provider that you like. But your primary care provider can do this procedure in their office. If you have a PCP who does not do a lot of pelvic exams, then personally I'd go to a gynecologist or midwife or someone who sees a lot of women. (Some of the primary care providers in the St Lukes system for instance refer anyone for anything gynecology -- most of those people are men).
Anyhow, I hope that helps and I'm sorry it took me so long to respond.
Kristin