Travelling from Delft to Antwerp

Hi! I have a question about traveling with the NS. I have the weekend free subscription and I’m planning to travel to Antwerp. I understand that I can use my OV chip and subscription for the part of the journey that takes place in the Netherlands (from Delft to Breda), and then get a separate ticket from Breda to Antwerp. My question is: Do I need to check in at Delft and check out at Breda using the card, and then check in again at Breda using a specific ticket? Or, is there an option to buy a supplementary ticket or top up my card, so that I could use this single key card for the entire journey's check-ins and check-outs? I was reading something about key cards and supplements but not exactly understanding this! I am also asking even if I want to go to Brussels airport for examples.