Worried

I am 1 week late and i have taken 2 pregnancy tests one just before i was due to start and the other 2 days after i was due to start. Both said negative... i am not having any symptoms of starting which i normally do about a week to a few days before starting. I am usually right on time. I was under some stress the week before but last time i was stressed i started 3 days late and had pms symptoms... i wake up feeling sick and have no energy the last 3 days. Should i test again? I have 2 kids already and neither pregnancy started this way. We have been actively trying for a 3rd