Clear Blue weeks indicator test

Soo, I tested positive on two early pregnancy tests earlier in the week.. yay! I’m thinking I’m about 4 weeks now. However my last period was very light and short which was unusual so I doubted if it was a true period or maybe some implantation bleeding. So, out of curiosity, I bought one of those weeks indicator pregnancy tests a couple of days ago to see if our conception time would match up to what I originally thought or my previous cycle. I was expecting the result to either be 1-2 weeks or 3+ weeks (since conception). The test showed 2-3 weeks?? Which makes no sense to either of the times I thought I would have conceived. I’m so confused. So, my question is how accurate are those tests? Has anyone else taken them? Were they accurate for you? If not, were you further along or not as far as they said?