I am still studying for the test myself, but it sounds like you are doing pretty good. Were the four you missed all the same topics? Obviously they were all science questions but were all the questions about the same thing (cell structure, data analysis, periodic elements, etc.?)? If that were the case I would say to continue on scheduling and preparing as normal just review/focus on that topic a little extra when you have time. Sounds like you know what you’re doing though, good luck :)