In the future, maybe switch to bi-weekly shots? This way you're not all over the place every week and also ask if your doc can prescribe you a few refills in advance this way when you see yourself getting low in the bottle you can go back to the pharmacy and get a refill without waiting the few days for the doc to send the new script each time.
Might be a better route than all the hassle it seems you are having now with the weekly thing going on. Also, set yourself some reminders, post it notes, phone alarms what have you. So you remember to do the shots ect.
I have mine in my phone to alarm me at the correct day and it even says which leg I'm supposed to inject so I don't forget that either.
As for labs, yes missing injections can set off your results. I'd recommend moving forward your lab date until you can consistently take your shots on a normal basis.