too early to test?

My cycle is 28 days, I'm never late I'm like clock work, I missed my period and had some spotting but that was like a week  ago and it was more like when I wiped but it didn't even last for an hour, however I thought my period was starting but it didn't, I'm on day 37 of my cycle, should I wait more to test? 
Also, I'm sexually active since I live with my SO which means I'm not really sure when i had sex