Hi,
This is a common problem - I kenah twice before also.
Please check your insurance policy because most policies would
cover the replacement of windscreens without affecting your
premium. Replacement of windscreen, if yours is a normal car
(meaning easy to get parts), takes just less than a day. But you
may not be able to park outdoors for the next 1-2 days to let the
sealants cure fully.
Recently, I had a friend who suffered the same thing, but the crack
was very small - unnoticeable at some angles. So what he did was
take a mallet and softly made the crack more prominent, then
claimed from insurance for the change of his windscreen. 