Went to Endocrinologist today

Ashley 👼👼💜 • Married to my best friend with twin angels watching over us (miscarried new years day at 12w3d.)

Went in for normal check up. When I told him that I had birth control removed on the 9th with no AF and I was pretty regular even on birth control. He insisted on doing a blood test..... I'm nervous, how long would it take to get a positive blood test if pregnant?