It's been 5 weeks since me and my gf had sex and she has no symptoms for the past 5 weeks and her stomach is not bloating or anything but her period is still not present this month and january almost ends. is this pregnancy or should i not be worried?

When in doubt best would be to test for pregnancy. While most of the time it proves to be a common menstrual cycle dysregulation, surprise pregnancies are still possible. There is no symptom(s) that will rule in or rule out pregnancy with 100% precision.

Conception occurs within day or so of the sex. It takes about 3 weeks for the embryo to make enough HCG for a positive pregnancy test. Blood test may be done a day after a missed period. Home pregnancy tests should be done 4-5 days after the missed period. If the result is negative repeat the test in 4-5 days. Use first morning urine and follow instructions for the test carefully.