Do I have a cockroach problem?

About three weeks ago, I saw a large cockroach on the outside of my house at night. I killed it and I never saw another one. We have been in our house for about three years and have never seen roaches or signs of roaches before.

I just finished spring cleaning (I did everything – wiped out cabinets, moved furniture, refrigerator, and stove, etc. and our house is very clean in general) I didn’t see any signs of roaches and didn’t see any in the cabinets or when furniture was moved. I wiped underneath the hot water base board behind the refrigerator with bleach and water and again didn’t see any signs of roaches except one dead one (although I’m not sure if it was a roach or not – my husband said it looked a little small and round to be a roach, but the body looked a little flat to be beetle?) I know this sounds a little crazy, but I just couldn’t handle it if we had a roach infestation. Should I be concerned that we have the beginning of a roach problem?

If this info helps, we live in the central Jersey Shore area in a single home, not an apartment.