Should i be safe about not being pregnant?

ok so me and my boyfriend first had sex about 2 and a half months months ago and at the time i was on the depo shot but due to the side affects i switched and had an implanon inserted 2-3 weeks ago and since then i have been having pregnancy symptoms such as morning sickness (ive threw up two mornings.) i use the bathroom more frequently, im constantly tired, im eating morem then my period came 2 weeks late. i took 2 pregnancy test about a week and a half ago and they both came back not pregnant. is this jsut side affects of the implanon or could i be pregnant?

Also after switching from the depo i was on birht control pill for a month(which i did not have sex during this month) and i had my period on the time it was suppose to come. could the birth control have made me have my period? or should i be safe about not being pregnant

thanks for the help.