I never really got anything but hardness until the end of Week 2 on 1ad/4ad, or even 1-test/4ad. You sound like you're doing everything right, just be patient.
I strongly suggest extending to 6 weeks. You will make your biggest gains in weeks 3-6, & a lot will be wasted cutting it to 4. The only time I'd recommend a 4-weeker is if you were gonna go 4on, 4off, 4on again.