Is it possible to take multiple otc pregnancy test and have them come out negative and still be pregnant?

I'm going 2 months w/o a period and I've taken like 6 to 10 pregnancy tests and they were different brands and they've all come out negative. I've beenhaving a few questionable symptoms and I'm going to see my doctor tomorrow... I'm just wondering if they can be that inaccurate or if anyone else has had a similar situation? Thanks!