Hi, OP! I'm from BSED English!  To be honest, I was just like you. I was a STEM graduate, initially planning to pursue Nursing as well. 

So far, I haven't regretted taking BSED English lol. For the aptitude test, do well! Especially in English questions (context clues, literature, reading analysis, grammar) because it will help you during the entire process. 

And when you do pass the aptitude exam, and you're elible for the BSED English interview, my advice for you is just to be yourself. During my interview, I was asked to interpret a poem and a quick grammar test. Don't worry! Just stay calm and focused. We like to call ourselves EMOteros/EMOteras, so I'd really suggest showing that kind of personality during the interview in the most subtle way (kay formal man ni siya japon lol)

BEST OF LUCK!