Super confused, 10 days late

so I started my period a friday had sex saturday night my period stopped for 2 days than continued until that friday. I bled lightly a week later and now I'm 9 days late my breasts are engorged and I'm having light cramping. I'm to nervous to buy a test because, well everytime I think I'm pregnant I take a test and get my period the next day. and I really want to have a baby. any thoughts on if maybe my body thought the second bleeding was my period? I don't know what to think. but I'm so hopeful yet scared to get a negative test again