I have lower front tooth pain since the past 3 days. is this because of sinus or gum recession?

Unlikely: Sinus infections or inflammation do not generally cause pain on lower teeth. Gum recession does not cause spontaneous pain, but instead may cause pain or sensitivity when eating, drinking or brushing. You need to see a dentist as soon as possible to determine the cause of your pain and render appropriate treatment.

Your pain: Is more than likely associated with gum recession, localized inflammation, exposure of root structure. If its in the lower anterior midline, could also result from a muco-gingival defect, requiring a gum graft and a frenectomy. Seldom does sinus involvement have an effect on lower anterior teeth. Best to bd seen by a dentist. All the best.

See your dentist.: Not sinus related. Could be recession related, or decay, or even trauma. To be sure you will want to see you dentist.

Sinus "toothache" : A sinus "toothache" is a type of referred tooth pain caused by an inflammation of the maxillary sinus or a sinusitis. The roots of the upper molar teeth in the back of the jaw may be too close to the floor of the maxillary sinus and you perceive sinus pain like a tooth pain. In your case the location of the tooth has no connection to a sinus. See your dentist for tooth pain.