There are a few things that can spoil your period week (which is Week 1 of your cycle), for instance, painful menstrual cramps and fatigue due to low estrogen and dipping iron levels.

However, unless you have severe menstrual cramps or anemia, these problems can usually be brought under control. For example, cramps can be eased with a heat patch, TENS unit or chamomile tea. And pep can be boosted by replenishing lost iron with iron-rich foods (such as enriched cereal, beans, lentils and spinach) or by taking a daily iron supplement (15 mg. for ages 14 to 18; 18 mg. for ages 19 to 50).

Thing is, reining in these menstrual problems rather than simply putting up with them is key, since it really can help you have a happier period. That’s because throughout your Week 1, estrogen is slowly rising, which gives your mood and outlook a lift as it makes its upward climb. Without Week 1 woes holding you back, you can fast-track your enjoyment of this hormonal surge.

Well, now I want to give you a heads-up about another period-related pitfall that has the potential to put a damper on your Week 1 so you can sidestep it:

A small 2013 study in the journal Perceptual & Motor Skills reveals that during menstruation we tend to perceive our body size as larger than it really is.

That’s what happened to the 44 female volunteers in the study. Choosing from drawings to represent various body sizes–from slender to obese–over the course of their monthly cycle, the women were far more likely to choose larger body images to represent themselves during their period.

However, body measurements taken by the researchers proved that these women were the same exact size all cycle long. They were no heavier during their period than at any other time in their cycle, nor were their stomachs or waists any larger.

So, why would we think we’re larger during our period if there’s no actual change?

The researchers speculate that it may be due to water retention, which can make us feel like we’re toting around more weight. Or, it could be self-consciousness about our period that, in turn, makes us more self-conscious about our body overall.

Whatever the reason for the skewed self-perception, the next time you feel doubt about your body size during your period, think about the results of this study.

This way, if you have body image issues, you can halt any negative self-talk or self-recrimination before it begins, which can help you have a happier period week.