What's wrong with this BJ strategy?

If you bet the min, say $1, if you win, you bet the min again, if you lose, you bet $3 next. If you lost, bet 7, if you lost bet 15. Then stop at 15 if you lose and bet $1 again. I figure you have more than a 50% chance of losing, but let's just say 50%. 0.50^4=0.0625 So the expected value of an average four hand series is 4*0.9375 - 26*0.0625 right? Isn't that +EV?