Can you tell if you're going to be pregnant with no symptoms and not tested yet (sounds crazy I know).

I remember first time trying for a baby I was on the pill for 3 years came off the pill and it only took me 2 in a half months and I was pregnant. I had this weird tummy feeling after i had sex like I felt really relaxed and obv my partner came inside it felt really weird and that I noticed a few things happened so I did test then found out I was pregnant.

Gave birth 21.02.2018 my baby is now 10 weeks and I'm back on the same pill took it for 3 weeks and I'm now on my 7 day break recently had sex and got the same thing as last time that weird tummy relaxed feeling could that possibly be a way of knowing withought testing to early or getting any early symptoms????