most pregnancy tests these days can give you an accurate result from the 1st day you miss your period. I would recommend buying one and if the result is positive, don't panic too much about spotting. Many women spot in the first few weeks which is known as implantation bleeding, where the embryo is attaching itself to the lining of your womb. And in some cases, you can have normal periods all the way through, although this is rare. Keep your doctors appointment though and if the bleeding becomes heavy in the meantime, go to the hospital as they may be able to give you a scan to check everything's ok. Best of luck!