I started menarche wheni was age 10. im now 13 yrs old and 4'11" im a transgender boy if i start hormone blockers could i attain some more height?

Doubt it: The growth expectation after menarche is 2.5 inches, most of which happens in the year after. The hormones that trigger menarche send messages to the growth centers to accelerate the push to final height. This closes the growth centers, and with closure there is no potential for additional height. Plan on being a short person, whatever way your heart takes you.