Late period but false negative?

Hi mummies! Just would like to ask for your opinions and advise on my experience that I'm currently facing. I am fairly regular in my period cycles, however I am 13 days late for my period from the expected day of my cycle. Not sure if it's part of the symptom of early pregnancy cuz people say that every pregnancy is different and when I conceived my first born 2 years ago, it wasn't like this. This is the first time I experience such case. Before my expected day of period cycle this month, I had a sudden high body temperature, thinking I was having a fever but with no other fever symptoms such as cough, flu and etc. So it was just a sudden high body temperature that increase and decreases in 3 days. Following after I had "recovered", I had nausea and strong sense of smell at times especially there was once when I entered my bedroom and it smelled like a strong medicine smell, but only I smelled it when none of my family members including my husband did. Then at times, I had this funny feeling in my tummy like I felt before during my first pregnancy... It feels like something is moving in my tummy. But I brushed off the thoughts from my mind cuz my tummy is still flat so it can't be right.. Also I had acne breakouts more than before and now started craving. What makes me more confused is that I had these weird symptoms but after 13 days of late period, still tested *Negative for pregnancy test*. My husband is pretty worried as well. We went to Poly last week to check up incase their medical stuff can detect for any possibilities but unfortunately it is still tested negative. So I would kindly ask for any super mummies advice or opinions about this🙏🏻 Thank you so much 😭🙏🏻