Help! Pregnant with third but don’t know how to tell partner

I’ve been using this app to track my period. My period has been absent for 37 days according to the app. I was wondering if it was ever going to come. So this morning I went and got a pack of tests and done one it shot up two thick pink lines. I was shaking. I have a 9 and 10 yr old. We are in the middle of converting our loft to make a room for each kid for their own space. This weekend I’m going on my cousins hen night I’m a bridesmaid. The wedding is in June 🙈 my partner has said several times no more babies. I don’t know what to do and how to tell him I don’t know how he will react. 😭 part of me is excited and part of me doesn’t want this