Speeding ticket question?

I received a speeding ticket for going 70mph in a 30mph on a country road... Now my lawyer says that i will likely have to do four days in the county jail(prosecutors recommendation)... I accepted responsibility for speeding and want to pay my debit to society BUT i have not seen the judge to get sentenced.... Now my question is can i just go up to the jail serve MY four days so when my court date does come i can have time served credit... I live in Florida my case is in Missouri... I cant afford to miss work again or the 300 dollar ticket to come here.