Should I tale blood test?

I had unprotected sex 2 weeks ago. my period was a day late, and when it came it was light and lasted 24 hours, and that was it. I had minimal cramping, and my hormones were everywhere. Normally my periods last 5 days, there is very heavy cramping and I'm usually average, but definitely not light on my periods until my last day. Usually I deal with PMS the week before, and hardly on my actual period. My husband thinks it is stress, but Everytime I've reacted to stress, my period would go longer. I took a test and it was a faint positive, but it was also possibly an evaporation line. 3 tests have came out negative after that. I'm thinking that maybe I should just get a blood test, or wait a week and test again? or should I give it a rest and assume I'm not pregnant?

**update**

test came back negative