Well it can be possible but we have to do some calculations to have a likelyhood.
For every menstrual period the ovulation occurs once and the ovarice produce an ova that has only a 24 hour lifespan. The sperm on the semen have a lifespan of 3 days aprox. So to get pregnant a woman must have sex during a period of six days, 3 days previous oand 3 days before the calculated ovulation date. To get your ovulation date you must substract 14 days from the date of your last menstrual periods. The longer the registers you have of your menstrual periods the more accurate the result. So lets say last month your period was of 28 day, before that 29 and before 28, you substract 14 day to each, and gives you 14, 15 and 14, the mean will be approx 14.3. Assuming you are alway regular add forteen days to the date that you started your last menstrual period and it will give you you approx ovulation date. Having 3 days after and 3 days before increases greatedly the chances of pregnancy.
This is the date method, used to calculate the days you can have sex unprotected. I know by first hand that it is really boring. And it is very error prone.
Do the math. You will have two outcomes. Either you had sex on the danger days or you didn´t.
Regardless of the solution you should do the next.
1: Do not have intercourse until the pregnancy can be ruled out
2: Do the urine test the day you espect you period but take the sample from the first void of the day (in the morning)
3: If you bleed do the serum pregnancy exam
It is very important (and very difficult) that you calm down. Pregnancy is almost completely asymptomatic the first 2 to 3 weeks since the pregnancy will be microscopical. Your symptoms are more likely to be from anxiety than from a baby.
I recomend you also to look for a doctor of your trust. Look for one that is eager to explain you everything on an easyway.