anything that causes your temperature to rise an extreme amount should be avoided. studies show that women who have an increase in body temperature during the first trimester have more babies with birth defects. Also, keep in mind it only takes about 10 minutes in a hot tub for your body temperature to rise to 102, which is too high, esp. when pregnant. I wouldn't stress to much about it since it was just once but i definitely wouldn't do it again if you find out you are pregnant.
I've heard thathot tubs should be avoided when pregnant but I doubt it could have done any harm for that short amount of time so early in a pregnancy.
hello.dont know about sauna,but hot tub beter dont doo,but if tub did somethng bad,you alreadyy feel thet...