Help/advice please

So me & my boyfriend really never use protection when we have sex. He always pulls out but the thing is sometimes he pulls out then wipes & goes back in. And sometimes I give him a blowjob & I swallow & he then sticks it in. Do you think you can get pregnant from doing that? I'm a week late & took 2 test but they were negative & I'm just a little confused because my period has never been late. I just need some advice.