I have similar trouble. However, there was usa stamp on my passport but not stamp in the canada side, and no record showing I re-enter canada. I couldnt remember if I was gone to USA. Later that night, I remember it was the stamp I got at an airport. After going through usa custom, my flight got cancel, I never had to go through canadian custom because I technically didnt leave canada. Anyways, luckily, I left Canada for usa again about 1 week later (according the stamp, but 1 day later in actual event, the usa custom made a mistake on the stamp date) and re-enter Canada the following week (this they have record showing I re-enter canada). Also, I have many extra days (280 days actuall pr + 365 days of pre-PR (as student and work permit)), the interviewer said it shouldnt be an issue. Plus she has a lot of common sense, she reassure me that it should be fine because my daughter was only 4 months old at that time, I wouldnt leave the country for too long anyways.
For your case, I think it would be fine. They have a record of you entering Canada. Dont worry about it too much. You have paystub, employment letter, credit card statements, phone bill to back you up. Dont worry. It is just time consumming. Good luck.
shocking. But all is well that ends well. Please update the spreadsheet (Feb 1).