Beta HCG rise concern. Rise concerning?

Wife's periods have been irregular. She has taken meds as prescribed by our doctor to regulate from time to time. We tried for pregnancy for 6 months without medicine. In Feb, doctor prescribed us both supportive meds to aid conception : Letroz 2.5, D2-D5 twice daily, Dubagest SR200, D16-D25 twice daily, MetPCO Care twice daily, All-9 once daily for my wife, and Fertisure-M twice daily for me. LMP on 17th Feb. Ovulation last detected in kit on 6th Mar. Brief spotting lasting few hours observed on 18th Mar. HCG done as per doctor's advice as follows - 20th Mar (44.1), 25th Mar (412), 28th Mar (583), 30th Mar (909), 1st Apr (1204). 1-2 tiny brown spots observed on 24, 25 & 28th Mar. Wife felt cramp 3-4 times over different regions of lower abdomen which lasted few seconds only. No spotting or cramp exists after 28th. HCG 1 & 2 was done from one lab, and HCG 3, 4 & 5 was done from another lab using different method and ref. ranges. Tried pregnancy 23.02-14.03. Is this HCG rise concerning?