Ive been taking metronidazole for just over 5 weeks..
two times a day (25o mg pre tablet)
if heard that it is carcinogenic...
is iot alright?

AS is true of many drugs, it has shown carcinogenic activity in animals. There's no data to confirm danger in humans. It's an extremely commonly prescribed drug and is considered safe. Here's one summary:

Metronidazole is reasonably anticipated to be a human carcinogen based on sufficient evidence of carcinogenicity in experimental animals (IARC 1977, 1982, 1987). When administered orally, metronidazole induced an increased incidence of lung tumors in mice of both sexes and lymphomas in female mice. Oral administration of the compound also caused mammary fibroadenomas and adenocarcinomas, and pituitary, testicular, and liver tumors in rats (IARC 1977, 1982, 1987). There is inadequate evidence for the carcinogenicity of metronidazole in humans (IARC 1982, 1987). Two epidemiological studies of women treated with metronidazole showed an excess of uterine cervical cancers, a neoplasm that has risk factors in common with vaginal trichomoniasis (for which metronidazole is administered). In one study, a greater excess of cervical cancer was observed in women with trichomoniasis who were not exposed to metronidazole compared to those who were exposed. One of the two epidemiological studies showed an excess of lung cancer; however, further analysis indicated that this excess could be due to smoking (IARC 1977).