I Have An Endometrium Thickness Of 12 On Oocyte Pick

I have an endometrium thickness of 12 on oocyte pick up. I am nearly 40 with no history of infertility having never previously tried to conceive but my partner had a vasectomy when with his ex-wife and ivf was our only chance to have a baby together. I was put on the lowest dose of ovarian stimulation. Pre-stimulation my FSH levels were 6. My partner, even though he had his vasectomy 19 years ago when he was 26, had a really good result from his MESA. What are my chances? I'm old I know. This is my first time with ivf. My doctor seems pretty confident but I keep thinking I'm nearly 40 and I keep freaking out.