Help!

So I’m kinda lost with this.. my SO and I have been trying for a baby. We do have other kids. I had my iud removed, had a period after! We literally have had sex everyday, sometimes even more than once a day, we both have high sex drives but as of today my period is 7 days late, I have all the symptom’s of being pregnant but every test I have taken says negative!

Ive read a lot of about other ladies having having the same problem most of all still don’t have an answer! And others stated that in fact they were pregnant just never showed up on a urine or blood test until they were 12-14weeks pregnant! HELP!!