A better plan would be to extend your cycle to more like 12 weeks. It will take at least 2-3 weeks to kick in and you need more time for muscle growth than just 5 weeks. I would also strongly consider increasing the dose personally. 500mg each week is typical for a first cycle. I see no point in going below 400.
I think you are just about as likely to have negative side effects at 250mg each week as you are at 400-500 mg ew. You just don't stand to gain as much muscle at the lower dosing.
Additionally, you may consider reducing your bodyfat percentage before starting the cycle. Reducing to 12-14% for example would allow for more room and more pleasing results than starting at 17%.
Also consider whether you may want to run a preventative anti-estrogen or aromatase inhibitor on cycle. I would definitely do so if I had my first Test E cycle to do over again. You can prevent gyno, reduce bloat and limit fat gain with the right AI or SERM. Do standard post cycle therapy with nolva/clomid starting about 2 weeks after your last shot. Also, consider cycle support or at least something to control blood pressure if it gets to be a problem (same with hair loss possibly if that is a concern).
Two injections per week are superior to one to keep blood levels stable (more stable mood, steady gains etc). If you are going to pin, it is no big deal doing two shots a week. For the cycle you are running you can put them all in your glutes if you want. There is a lot of room to move around back there.
