Is there a reason not to double dose? Is it the side effects?
I found this study that showed my 4 days of protection will be pretty comparable to the usual 7 days (97 to 98% reduction in risk):
According to levels of drug detected in peripheral blood mononuclear cells (PBMCs), and comparisons of those results to drug levels estimated in previous research to correspond to varying degrees of protection against HIV, one day on PrEP led to a 75 to 91 risk reduction, three days meant a 95 to 97 percent risk reduction, and five and seven days translated to a 98 to 99 percent risk reduction. The presumed risk reduction stayed higher than 90 percent for seven days after the last dose.