How do you tell if it’s a chemical pregnancy?

Angela • 44 yr old Mother of 3 older children to previous marriage & a 4 year old boy to my partner of 5 yrs, ttc no 5 for 2 years, did fall pregnant last year in June but lost the baby at 12 weeks. Now Just had my baby boy Heath William 13/03/20 😍

I had a very faint positive test yesterday, temp was 36.37, but today it rose to 36.61? However I got my period 😢 I’ve never had high temp with period, anyone else had this?