Pregnant while taking progesterone only birth control?

Hoping to get some insight from other Progesterone only birth control users. I switched from an IUD to progesterone only pill at the beginning of February. Got my period about a week and half after taking them. Then I stopped taking them the 4th week because I was under the impression these pills were the same as combination pills. 🤦🏼‍♀️ However, My midwife informed me that all the pills have active hormone in them while the combination pills have 3 weeks of active and 1 week of placebo. So I wasn’t good about taking them at the same time plus went a WHOLE WEEK without taking them and had sex during that time. I am now having some pregnancy symptoms but got a BFN this morning with a home test. Could those symptoms mean I am actually pregnant even though I got a negative test?