You can but your results won't be very accurate.
First response is only 63% accurate 4 days before your period is due (5 before it is late). It's only 99% accurate from being one day late. Clearblue is only 1/2 as sensitive as First Response.
And this is if you produce enough to come up positive on a urine test.
If you use your first morning urine it's more concentrated and you'll get a more accurate result.
I used first response 3 days early and got a positive.
good luck