Pregnant?

My boyfriend just told me that everyone has noticed a change in me. His parents both have asked if I am because I look different; as in a glow and just look better. I haven't changed anything about myself so idk what they see. But it's not only them, I saw my boyfriends friend who I haven't seen in around 6 months and he asked him if we have been safe and we have not. We have had unprotected sex 4 times since the 17th. I took a test on the 20th but I it was negative then I got my "period" but there wasn't any cramping like usual and it lasted 4 days.