You can wait a few days and test again. If you are not pregnant this month, the robitussin is best used during the 5 days before you ovulate. The guafensin in the robitussin thins out your cervical mucous, just as it thins out chest congestion and mucus, so it helps for easier passage of the sperm during your most fertile days. There's really not much benefit to taking it after you've ovulated. Vitamin C for you and your partner will also help with your fertility. It will thin out his seminal fluid and thins your cervical mucous, helping the sperm make the journey. Plus, it boosts your immune system, which helps your body all around.
Good Luck
Hi!
MOST of the pregnancy tests that are available over the counter will become positive at about the same time as the period is missed. If you were my patient, I would advise you to repeat the test since you are late. I usually tell my patients not to test until they are late for their period, just to save some $$$. Good luck!
Dr B