Baby Sleep: Frequent Waking
You asked: "Is this a stage?" The answer is YES! All babies become more wakeful, fussy and irritable as they approach 6 weeks of age. This is six weeks after the due date or 46 weeks after conception. Especially in the evening or night, they become increasingly more unsettled and sometimes cry for no apparent reason. During their agitated wakefulness, they swallow air so they become gassy. The gas is a consequence of the fussiness and not the cause of fussiness. These behaviors occur in all societies and are independent of parenting practices. For more information on what is going on, read, or have your husband read, Your Fussy Baby.
Do whatever you can to soothe your baby day and night. You cannot spoil your baby. Get help so you can take breaks to recharge your battery. This is smart, not selfish, because you are the main source of nurturing your baby and you cannot do a good job if you become entirely sleep depleted yourself.
At about 6 weeks of age after the due date, start to practice an earlier bedtime of 6 to 9 PM and you will see longer blocks of night sleep, each lasting 4 to 6 hours, usually occurring before midnight. This is the beginning of the development of the circadian rhythm for a baby's night sleep. Watch for drowsy signs and catch the emerging wave of drowsiness before she develops a second wind. Perfect timing produces no crying but it takes time and practice to get it down right. Please be patient.