Flu like symptoms are not signs of pregnancy. You should be checked by the doctor. In fact all signs of pregnancy in a woman also mimic with many other conditions. No sign of pregnancy is authentic. Whenever, a woman miss her period and she is sexually active and is not on contraceptive protection then pregnancy can be suspected. If this is a case with you then take pregnancy test either in urine or blood. But remember, pregnancy tests should be conducted after missing of periods otherwise false negative results are expected. So, get pregnancy test and visit a doctor if test is negative.