YES. u can bring ur old I-20

Don't worry, many people do this. This rule works for people who changed their status from F to H too.

They may replace your old I-94 with a new I-94 when you come back or they may not. Still it is no big deal. But better make sure you have a copy of your old I-94 for your file, because once they replace it, you won't have any record of it.