Okay 2 years ago I got a scrape for sliding in soccer on my shin and it got infected and i got some prescribed cephalexin. Now present day 5/25/15 I got the scrape on the same spot again for sliding and it is swelling and probably infected. Is it okay to take the cephalexin even though it says "discard after 3/30/2014" since its 5/25/2015?