Three weeks pp

I'm three weeks pp and I had sex a two weeks pp I know it's wasn't the brightest idea at all and it was unprotected with my husband and he didn't pull out and then we just had sex last night and he didn't pull out I'm stressed out I might be pregnant again so I took a pregnancy test and it was negative is the test accurate or do I need to take another????? I don't need any negative comments and I feel bad about already