Sounds like insertional tendinitis more than a muscle pain.

Note: The hamstring is attached onto the pelvis and poor movement of pelvic joints will inhibit nutation (nodding) of sacrum. Getting this joint moving well can help a great deal.
While I can't be specific this Chiropractic approach of pelvic manipulation helped Bradly Wiggins and might help your recovery.

Otherwise, if things have now not changed after 4weeks - I would seek a form of tendon stimulation and eccentric loading of hamstring muscle.

Tendon stimulation can be ultrasound therapy or shockwave therapy.

It may also be beneficial to look at your saddle height a raise of less than a inch could open the hamstring up enough through repetition.

Lastly compressive support can be very benifitial to hamstring recovery and reduce some pressure to the tendon insertion.

Hope that helps,

Written on cracked iphone, please excuse any spelling errors!!😉

Niall Marshall-Manifold D.C.
Wimbledon Chiropractic & Sports Injury Clinic