I would wait closer to the first week of February, maybe the 3rd or 4th. Most pregnancy tests detect a specific hormone in the urine and require a specific amount before they turn positive. Your body slowly start to produce this hormone, and thus discard it into your urine, as your pregnancy starts and the production will continue the further into it you go. If you test too early then you will a false negative because there wasn't enough hormone is turn the detector positive.
Good luck.