P17 shot, contractions, ugh

Okay, so I go every Friday and get a p17 shot to keep me from going into labor early, well I'm 25 weeks and for the past two times I have start having contractions the day before I get my shot, last was at night and lasted about an hour, this time it's 3:47 in the day and it's already started. They are worse than last time but not enough to even think about going to the hospital, I've been drinking lots of water, laying on my left side, and trying to relax, but they are still coming. I'm home alone with a 3 year old and a 2 year old. I go to the Dr next Tuesday. What should I do?