In the process of IVF, the practitioner needs to shut down hormones. The most recent and updated protocols are patient-friendly and you rarely experience any of those side effects. The next step is to stimulate the ovaries in order to recruit eggs and this happens with another set of hormones. these hormones are not different from the ones your own body produces and they work the same way. However, the dose is different. Hormone levels will need to be increased to support the growing follicles and eggs. The stimulation of multiple follicles will in turn increase the internal production of estrogen which is the main reason of the side effects. Estrogens may cause boating, nausea, feeling of fatigue and mood swings. These side effects are similar during the preparation for transfer for the same reason. Women who will get pregnant at the end of this process will experience these symptoms that will endure because pregnancy has the same side effects. Some would extrapolate that some residual hormones remain but this is not the case. If planning for a subsequent embryo transfer, there will be a waiting period, thereby a point where the body will flush out all the hormones it has produced and reboot. Choosing to proceed to a fresh embryo-transfer, will cause the body that is already producing the necessary hormones to support the future pregnancy until the placenta kicks in.
Mood swings is a very definite side effect of IVF. It is the result of elevated hormone levels but rarely last longer than the IVF round. Variables such as anxiety and subconscious stress also interplay which produce mood swings. A failed IVF round should be evaluated before retrying. Therefore, IVF is a procedure that can be repeated but a period of a month or two should be realized for rest and evaluation before undergoing again. In addition, 17% of couples who are planning to have IVF will get pregnant before or in between IVF rounds. The most probable reason is that your body is boosted from the previous treatment so it regulates the timing of ovulation. Therefore, in conclusion having knowing of what changes the body will experience will aid in realizing the physical and emotional effort that is required.
Ref:
https://www.ivfbabble.com/how-do-you-stay-balanced-when-your-hormones-have-a-different-idea/ 
