I found a bed bug in my house

I haven't traveled anywhere in more than a year because me and my family take turns in taking care of grandma. I haven't been in a hotel, cinema, taxi, bus, airplane either

I found it on my potty seat on it's back trying to right itself up. I thought it's a ladybug at first since it was round and clumsy and put a finger above it to let it grab it. But it wasn't a ladybug, it was brown, flat and had a weird segmented body. After killing it and googling it's definitely a bed bug. There's a little vent above my potty that has a iron mesh with pretty big openings, I think it dropped down from there and fell on the potty seat, I was just lucky to catch it on time

What if more entered my house last night or the day before? I don't want a bed bug infestation