I have been working as an RA for the past two years in an academic medical center, and when I was applying for RA positions my senior year, I sent out about 10 applications a day from January to April before I started hearing back from anyone. I think jobs tend to start the hiring process only a couple months before they need the position filled, so February may be a little early if you only graduate in May. Also, I highly recommend going to job recruitment fairs at your university--that's how I got hooked up with mine. I was able to hand my resume to the HR representative in person and he sent it to every psychology research lab in the hospital. It worked out much better than simply applying for openings posted on university or hospital websites, although those did get me a couple of interviews as well (2 interviews out of about 200 applications I submitted...). Good luck!
