I'm not sure how to deal with this.

Hello there, I'm 10 days late on my period. I already took two pregnancy tests within the last week and all came back negative. As a broke college student enrolled in a very busy summer semester, I asked my boyfriend to purchase more HPTs since I can't afford anymore(I'm literally down to my last $20 until two weeks). My boyfriend complained and said no. I'm absolutely anxious about this.. Should I just use some of the $20 I have left? Should I just pester him? Is there any organization that'll do a pregnancy test and possibly accept payments?