test is tomorrow. opinions?

I've been reading this forum for 3 days. Congrats on making it an awesome, trustworthy source for info.
I've been told we will be drug tested on the 4th at work. They are coming to our facility. (clinic sold to hospital). I will be 9 days clean. I'm 40, 5'6 and 135lbs & though i smoked daily, it wasn't much...just a few hits from a one hitter usually.
I can get substitute urine from my kid... but worried about temp & storage as we don't know what time of day they will be there. I bought xxtra clean the day I found out, but again, don't know what time they will be there & afraid I'll miss the window of "clean"..or test too dilute. Just out of curiosity, I took a home test today, and I passed!! just barely a line...very light, but definitely a line. So, I'm going to test again in the morning with first morning urine. (I had drank a few cups of coffee & couple glasses of water over about 2.5 hours before I tested today). So here are my questions. 1. If it passes, would you skip subbing or diluting & trust it? 2. if I don't pass with first void of day, what do you suggest seeing as I'm at work for 9 hours a day & have no clue what time this will happen? Thanks in advance. I will post updates & results.

wanted to add.. I live in a small town. had to drive 40 miles to get xXtra clean..wouldn't have bought it if i had read here first! I couldn't find creatine supplements and I've been sick this weekend and didn't eat red meat except for a burger 2 nights ago. I want to use the dilition method...but have no creatine (too late now anyway) & not sure if it will last being that it could be end of day before I'm tested.

If you pass using the first void in the morning, then don't worry about subbing or diluting. You'll be fine to pass your random test. If not, I would go the sub route. Maintaining temperature is not as hard as it sounds. It can however be uncomfortable carrying the sample all day. If you can keep the urine close to your body(preferably touching) you'll having no problem keeping the temperature at 96-98 degrees. You'll want to find a flat travel size shampoo bottle, almost like a Elmers glue bottle, but smaller. Along with this, you'll need a handwarmer and a rubber band to affix the warmer to the bottle. You'll also need a temperature strip. You can find the ones that are made for use on baby's foreheads. They work great and you stick it right on the bottle. Most people prefer to wear two pairs of tighty whiteys and secure the bottle under the nether region. I prefer the strap the bottle to my inner thigh with an Ace bandage(not saying this is the way to do it, just what I prefer) but that is up to you. It's all quite simple, just practice as much as you can. You can fill your bottle with water, crouch it a get used to walking around with it, all while checking to see how fast your temperature is increasing.
Make sure you obtain your donor urine right before you go to work. Human urine starts to break down after 8 hours.