Understand the constellation to help explain, what is Niu Yi Niu Er Niu San, I am Wu San Niu.

4/ 19-24 is Aries and Taurus.

4/25-5/2 is Taurus 1

5/3-5/ 10 is Taurus 2.

5/ 1 1-5/ 18 is Taurus 3.

5/ 19-24 is Taurus and Gemini.

Therefore, you are Niu Er.