It does not happen that fast. My partner was in similar situation - his ex wife reported him to CBSA/IRCC and he got deportation order. But they do not ship you immediately. When you go there, it will be to introduce your case. You have to take with you all your HC evidences showing how your child needs you in Canada. Take him with you, if you can. Ideally, it is good to have AOR showing that your HC is in process, but if you don't have it yet, bring all evidences you can and tell them you are almost ready to apply for HC. They may offer you to apply for PRRA, which will give you extra 6-12 months to sort out your HC, or they will give you removal interview date (a meeting where they will propose to you a travel itinerary), or they will tell you to do weekly/monthly check-ins until further notice. All this to say: don't panic, gather all evidences and be prepared to ask your CBSA officer for compassion. It's not over yet. Many of us went through this on this forum and we overcame it.